Table of contents

This paper reviews the recent progress in GaNAsSb material for photonic and electronic applications. All the results and data presented in this review article are summarized from our previously published works in refs. 6-12. Photoresponsivity of 12A/W and cut-off frequency of 4.5GHz were achieved in the 1.3μm GaNAsSb based photodetector. A GaNAsSb/GaAs optical waveguide system was also demonstrated at 1.55μm. The GaNAsSb based photoconductive switch exhibits pulsed response with FWHM of 30ps and photoresponse of up to 1.6μm. The turn-on voltage of the device fabricated from GaNAsSb based HBT is ~330mV lower than that of a conventional AlGaAs/GaAs HBT.

AlGaN/GaN high electron mobility transistors (HEMTs) with Ag/AgCl gate are found to exhibit significant changes in channel conductance upon exposing the gate region to various concentrations of chorine ion solutions. Ag/AgCl gate electrode, prepared by potentiostatic anodization, changes the electrical potential when encounters chorine ions. This gate potential changes lead to a change of surface charge in the gate region on the HEMT, induced a higher positive charge on the AlGaN surface, and finally increases the pizeo-induced charge density in the HEMT channel. These anions create an image positive charge on the Ag gate metal for the required neutrality, thus increase the drain current of the HEMT. The HEMT source-drain current showed a clear dependence on the chorine concentration. The limit of detection (LOD) achieved was 1×10-8 M using a 20µm × 50µm gate sensing area.

Prior to the deposition of the Ni/Au interdigital electrodes, the GaN surface of GaN/AlGaN metal-semiconductor-metal (MSM) ultraviolet photodetectors was chlorine-treated. The low frequency noise equivalent power of the chlorine-treated photodetectors, measured at a bias of 5 V, was 5.13×10-10 W, which was one order of magnitude lower than that of the photodetectors without chlorination surface treatment. The normalized detectivity of the chlorine-treated photodetectors was 6.16×108 cmHz0.5W-1, which was higher than that of untreated one. The dark current of chlorine-treated and untreated photodetectors, operated at 5 V, was 1.45×10−11 A and 3.68×10−11 A, respectively. The performance improvement was attributed to the passivation of GaN surface by chlorination treatment.

At the 2009 San Francisco meeting, the State of the Art Program on Compound Semiconductors (SOTAPOCS) will be held for the 50th time. This manuscript provides some personal recollections of the place that wide bandgap materials have played after the early days of the symposium were focused mainly on GaAs and InP materials and devices and how this highlights the corresponding maturation of the compound semiconductor industry.

Antibody-functionalized, Au-gated AlGaN/GaN high electron mobility transistors (HEMTs) were used to detect c-erbB-2, a breast cancer marker. The antibody was anchored to the gate area through immobilized thioglycolic acid. The AlGaN/GaN HEMT drain-source current showed a rapid response of less than 5 seconds when target c-erbB-2 antigen in a buffer at clinically relevant concentrations was added to the antibody-immobilized surface. We could detect a range of concentrations from to 16.7 μg/ml to 0.25 μg/ml. These results clearly demonstrate the promise of portable electronic biological sensors based on AlGaN/GaN HEMTs for breast cancer screening.

Device performances of GaN-based flip-chip light-emitting diodes (FC LEDs) with planar and patterned sapphire substrates (PSS) were compared in this study. It was found that for the FC LED with planar sapphire, enhancement factor of luminous intensity can be raised to 107.5% after the processes of substrate removal and surface roughening. By contrast, for the FC LED with PSS, the intensity enhancement factor is already up to 169.5% without any post-processes as compared with the intensity of an as-fabricated conventional FC LED. Further intensity improvement to 205.1% can be achieved for the FC LED with PSS by employing subsequent processes such as substrate removal and surface roughening. These results indicate that the PSS approach is useful in improving light extraction of a nitride-based FC LED.

Gate-recessed AlGaN/GaN MOS-HEMTs were fabricated using a photoelectrochemical (PEC) method to form the recessed structure and to directly grow gate insulator on the recessed surface. The resulting devices exhibited better performances than conventional one without gate recess, including a saturation drain-source current of 642 mA/mm, and an off-state breakdown voltage larger than -100V. The normalized noise power spectra of both kinds of devices at the saturation region were well-fitted by the 1/f law and the Hooge's coefficient α in both devices was about 10⁻⁴, demonstrating that PEC wet etching is an effective way to achieve a damage-free surface and to improve the DC characteristics of the MOS-HEMTs.

The history of III-V semiconductors in RF applications is more than forty years long. It began in epitaxially prepared diodes based on unique physical properties for certain applications including the "Gunn" effect as well as the higher mobility of an electron when compared with silicon. This gave way to planar processing and ion implantation which permitted the realization of the monolithic microwave integrated circuits (MMICs). Digital wireless applications have become the most ubiquitous applications for III-V RF devices. This was facilitated by taking advantage of not simply the mobility advantages of III-V semiconductors but also the unique properties available through the use of different combinations of active layer alloy compositions. This has driven wide market acceptance for pHEMT and HBT based electronics used in every day life.

Peltier element cooling is demonstrated to be an effective method for collecting exhaled breath condensate (EBC) on AlGaN/GaN High Electron Mobility Transistors (HEMT). The HEMT sensors have functionalized gate areas for glucose and pH measurement. The current change measured in the HEMTs with EBC shows that the sensitivity of the glucose detection is lower than the glucose concentration in the EBC of healthy person and the pH measurement range includes 7- 8, typical of that for human blood. The sensors can be integrated into a wireless data transmission system that allows remote monitoring. Details of the transmitter and receiver design for the transmission system are given. Our work demonstrates the possibility of using AlGaN/GaN HEMTs for extended investigations of airway pathology without the need for clinical visits.

Heterostructured, composition-adjusted Au-CdTe-Au nanowires were fabricated via templated electrodeposition. Cd/Te ratios were modified in the wires by varying the Te4+ concentration in the deposition electrolyte. These wires were characterized by energy-dispersive x-ray spectroscopy (EDS); subsequently, they were deposited onto Si/SiO2 substrates and electrically contacted using Pt deposition in a focused ion beam tool. EDS and photoelectron x-ray spectroscopy (XPS) were used to characterize the composition and surface chemistry of CdTe films deposited from the various electrolytes.

The reliability of GaN-based transistors has improved over the last decade into a system insertion ready technology. Material quality and uniformity has played a strong role in this evolution. Identifying and understanding the physical evolution of the degradation mechanisms provides a basis for evaluating device lifetimes. Recent life testing has demonstrated sufficient lifetime for most applications.

AlGaN/GaN high electron mobility transistors (HEMTs) were used to detect botulinum toxin. The gate area was deposited with Au and thioglycolic acid. The antibody was anchored on the gate area. The AlGaN/GaN HEMT drain-source current showed a rapid response of less than 5 seconds when the target toxin in a buffer was added to the antibody-immobilized surface. Different concentrations (from 0.1 ng/ml to 100 ng/ml) of the exposed target botulinum toxin in a buffer solution were detected. The sensor showed low detection limit of less than 1ng/ml and saturates above 10ng/ml of the toxin. The sensor was recycled with the phosphate buffered saline (PBS) after the toxin detection and still showed the same sensitivity.

NiSi as the electrode of ZnO films was annealed for different temperatures. It was found that with the increase of the temperatures, although the structure quality of ZnO films does not change greatly, the optical properties of the films do indicate the introduction of the oxygen defects into ZnO films by annealing process.

Iron oxide n-Fe2O3 nanowire thin films were synthesized by thermal oxidation of Fe metal sheet (Alfa Co. 0.25 mm thick) in an electric oven then tested for their photoactivity. The photoresponse of the n-Fe2O3 nanowires was evaluated by measuring the rate of water splitting reaction to hydrogen and oxygen, which was found to be proportional to photocurrent density, jp. The optimized electric oven-made n-Fe2O3 photoelectrodes showed photocurrent densities of 1.32 mA cm-2 at measured potential of 0.0 V/SCE with photoconversion efficiency of 1.69 % at applied potential of 0.70 V vs Eaoc (electrode potential at open circuit conditions) under illumination intensity of 100 mW cm-2 from a Solar simulator with a global AM 1.5 filter. The photoactivity was improved upon incorporation of carbon into the lattice of n-Fe2O3 by flame oxidation at 850{degree sign}C. The carbon modified (CM)-n-Fe2O3 showed enhanced photocurrent response to 3.14 mA cm-2 at a measured potential of 0.0 V/SCE with an efficiency of 2.23% at applied potential of 0.52 V vs Eaoc. The nanocrystalline CM-n- Fe2O3 and n-Fe2O3 nanowires thin films were characterized using photocurrent density measurements under monochromatic light illumination, UV-Vis spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Recent studies show that hydrothermally grown ZnO nanorods can modulate cell adhesion and survival on various substrates. Hydrothermal growth of ZnO nanorods on biliary stents and nitinol wires used in metal stents is demonstrated. The nanorods can be conformably coated with silicon dioxide using low temperature plasma enhanced chemical vapor deposition (PECVD) system to reduce immunogenic response. In addition, the control of nanorod density is demonstrated by using a surfactant, Triton X-100. These results show promise of using nanorod array to control cell adhesion and viability on implantable devices.

M-Al2O4:Eu2+ (M: Ca, Sr) thin films were deposited on c-plane sapphire substrates by rf magnetron sputtering, and growing behaviors and luminescent properties were investigated. As-deposited films were amorphous-like, but they were transformed to the epitaxial films by annealing at high temperatures. The epitaxial orientations and growing behaviors of CaAl2O4 and SrAl2O4 films were different each other due to the crystallographic distinction. PL spectra exhibited a blue and a green emission for CaAl2O4:Eu2+ and SrAl2O4:Eu2+, respectively.

We report the observation of self-limiting process in the atomic layer deposition (ALD) of zinc oxide (ZnO) films on (0001) sapphire substrates at low temperatures using diethylzinc (DeZn) and nitrous oxide (N2O). I was found that a monolayer-by- monolayer growth regime occurred in a range of DeZn flow rates from 5.7 to 8.7 μmole/min. Furthermore, the temperature window for the self-limiting process of the ALD-grown ZnO films was also observed ranging from 290 to 310 °. The transmission and absorption spectra of the ZnO films prepared in the self-limiting regime show good optical characteristics with tramsmittance being more than 80% in the visible light region. Experimental results indicate that ZnO films grown in the self-limitng regime all exhibit improved materials characteristics and thickness uniformity.

The implementation of terawatt photovoltaic solar energy conversion will place new demands on materials supply and environmental impact. As a consequence, the search for sustainable photovoltaic materials that combine low cost with low toxicity and low energy manufacturing processes is becoming increasingly important. This paper examines the preparation and properties of two merging indium-free photovoltaic absorber materials, Cu2ZnSnS4 and Cu3BiS3. Electrochemical routes to fabrication of absorber layers are considered, and characterization methods based on photoelectrochemistry and electrolyte contacts are discussed.

The growth process of Cu-In-Se compounds was investigated by in-situ electrochemical techniques and ex-situ XPS and Raman spectroscopy. The growth can be divided in three well separated steps. In a first stage, the Cu concentration is high, leading to the formation of a Cu-rich binary phase, Cu2Se, which acts as a precursor for Se(IV) reduction into elemental Se(0). When the surface concentration of elemental Se(0) is high enough, a new surface phase is formed with a stoichiometry close to CuSe2. It acts as a catalytic site for indium incorporation. This results in the formation of CuInSe2 and Cu-poor chalcopyrite phases. The proportions of the different phases evolve during the growth. This complex mechanism is in agreement with the compositional, structural and electrical properties of the samples as a function of the thickness.

This paper reviews our recent work about gold electrodeposition on H-terminated Si(111). It is shown that Au(111)/Si(111) epitaxial layers are grown and that the film morphology can be varied according to the deposition conditions (potential and solution pH). At pH = 14 (cyanide solution) selective gold nucleation at the substrate monatomic step edges is observed. A homogeneous nucleation is obtained at pH 4 (chloride solution). In the former case 3D growth occurs and in the latter case ultra smooth buffer layers are obtained. Application of these substrates to formation of magnetic nanostructures with tuneable properties is demonstrated.

Ordered nanocrystal assemblies are an exciting new class of materials where electronic, optical or magnetic properties can be dictated by tuning the position and ligand environment of each nanocrystal structural unit. Device integration in both nanoelectronics and nanophotonics relies on the ability to locate these ensembles with nanoscale accuracy exactly where they are needed. In this paper we overview our recent work in the area of electrophoretic deposition of charged nanocrystals from toluene.(1, 2) The systems discussed are twofold 1: gold nanocrystals (8 nm) which are positively charged and assembled from a toluene solution with unprecedented selectivity into lithographic channels and 2: CdS nanorods (100 nm × 8 nm) which are negatively charged and assembled into perpendicularly oriented nanorod superlattices over centimeter squared areas suitable for nanorod solar-cells.

InP surface are treated in K2PtCl4 dissolved in pure water. A spontaneous electroless process is observed with interesting residual Pt(0) coverage an correlated InP oxidation. The demonstration of this effect is given by high resolution XPS. Modifications are also detected using capacitance measurement on the interface.

The formation of self-assembled monolayers (SAMs) by suitable organic molecules with appropriate anchor groups on semiconductor surfaces may be used either to probe both the chemical state and the quality of the surface or to achieve surface passivation. Molecules with thiol anchor groups are able to bond to hydrogen-terminated germanium surfaces (Ge-S bond). We have prepared SAMs of alkylthiols with trifluoroacetate head groups on germanium. The germanium surface prior to and after SAMs formation has been characterised by Near-Edge X-Ray Absorption Fine Structure spectroscopy (NEXAFS) with synchrotron radiation in the PTB laboratory at BESSY II. We succeeded in assigning S-NEXAFS peaks to the Ge-S bond formed during self-assembly and were able to distinguish between different fluorine species via F-NEXAFS.

A new route of InP passivation was clearly ruled by an anodic electrochemical process in liquid ammonia as a relevant nonaqueous solvent. The coupling approach using both galvanostatic control and XPS analyses evidenced that this first protective film upon InP was definitely associated to one coating monolayer of general formula [ (H2N)P=N-]n. The electrochemical stability of the complete covering thin film was tested during hydrogen evolution in HCl aqueous solution. In spite of the high cathodic charge, unexpectedly no cathodic decomposition of the coated InP semiconductor was detected by XPS analyses. The electrical conductivity of this protective film and its electrochemical stability under negative overvoltage was then reported. In contrast to a bare InP, the electroless immersion of the protected InP in K2PtCl4 solution did not lead to the formation of metallic Pt cluster onto the substrate. On the contrary, the presence of amino groups in the film offered a unique opportunity for Pt (+II) grafting. A hybrid inorganic structure was proposed from the N/Pt atomic surface ratio, slightly higher than 2.0. The stability of the covered InP substrate as well as the ultra thin passivated film upon functionalization were also demonstrated from XPS analyses.

Optimization studies of lead selenide (PbSe) nanofilm formation using electrochemical Atomic Layer Deposition (ALD) are reported here. IV-VI compounds semiconductors, such as the lead chalcogenides (PbSe, PbTe and PbS), have narrow band gaps and crystallize in the cubic rock salt structure. They are of interest for their optical and electronic properties, which make them useful in thermoelectric device structures, infrared sensors, and photovoltaics. PbSe has the narrowest band gap of the lead chalcogenides, 0.26 eV at room temperature. PbSe deposits were formed using an ALD cycle on Au substrates, one atomic layer at a time, from separate solutions, containing Pb or Se ions. Single atomic layers were formed using surface limited reactions, referred to as underpotential deposition (UPD).

Depending on the applied electrochemical parameters, various anodic films can be grown onto InP in aqueous media. In borate buffer at pH = 9, the formation of homogeneous and thin InPO4-like films occurred when anodic treatment is performed with a low current density, while with higher imposed current configuration porous and thicker layers are grown. In this work, AFM measurements coupled with XPS analyses and capacitance-voltage investigations have been used to study the relationship between morphology, composition and electrical properties of different anodic oxide films performed on InP surface, with current densities ranging from 1 mA.cm-2 to 100 mA.cm-2.

The reaction of activation of acid-terminated organic monolayers grafted on (111)Si surfaces into succinimidyl-ester terminated monolayers by treatment in N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) has been studied by infrared spectroscopy and its kinetics have been followed in situ. The reaction exhibits non exponential kinetics, with an initial fast rise in the appearance of succinimidyl ester followed by a long reaction tail. The origin of this behavior can be ascribed either to the existence of a fast reaction pathway involving anhydride formation, or to the rate limitation by steric hindrance effects. The subsequent amidation of the succinimidyl ester layers by a primary amine has been studied similarly. Here, the kinetics are found to be exponential, but the reaction rate exhibits a sublinear dependence on the amine concentration. This behavior is ascribed to the effects of electrostatic interactions on the adsorption of the protonated amine onto the Si surface prior to reaction.

A layer of porous InP is grown beneath a thin dense surface layer when n-InP electrodes are anodised to sufficiently high potentials in aqueous KOH solutions. The shape of the linear sweep (LSV) or the cyclic voltammogram (CV) is dependent on carrier concentration. A technique is presented to deconvolute the effects of potential and time on a CV. The results obtained from this technique are used to explain the shape of the anodic current response and it relation to porous layer formation. The accuracy of the deconvolution technique is then tested by comparison to experimental results.

In this paper we report, for the first time, a galvanostatic control in 1M HCl aqueous solution onto a InP surface that had been previously entirely nitrogenated. The surface nitrogenation required an anodic electrochemical treatment in acidic liquid ammonia (NH3 liq.). An homogeneous covering film with " P-N " terminations was obtained onto the InP surface properly deoxidized. This thin film is notable for its lack of air ageing and also for its chemical stability in HCl. A galvanostatic control at different current density (10 mA.cm-2, 100mA.cm-2 and 300 mA.cm-2) in 1M HCl was used to identify the effect of this " P-N " terminations on the porosification process. In comparison to a bare surface, a contrasted evolution of the interfacial potential was clearly observed for low current density. As expected, a crystal oriented pore morphology (CO) is obtained onto a bare InP surface whereas "oscillating" current line oriented pore morphology (CLO) is kept onto a surface entirely recovered by a " P-N " film. The presence of the nitrogenated film can therefore be significant on the pore growth evolution in 1M HCl aqueous solution.

In this paper, we report an unexpected dissolution phenomenon at n-InP electrodes during porous etchiong in 1M HCl under potentiostatic consitions (5V vs. Ag/AgCl). Although the scanning electron microscope examinations show the typical tubular and regular pores that exhibit a depth proportional to the anodic charge, further chemical analyses of the dissolved material performed after the pores formation by atomic absorption spectroscopy reveal a dual dissolution process. An electrochemical etching process exhibiting a valence of 8 is evidenced. Howeverit is surprisingly coupled to a chemical dissolution that correspnds to the half the dissolved InP.

In this work, the growth of crystallographically oriented pores in III-V semiconductors has been investigated. Based on new and previous results a model for pore growth has been developed, which is mainly based on a stochastic branching probability of the pores. The stochastic nature of the model allowed to implement it as the core for Monte-Carlo-Simulations of pore growth. The simulations were able to reproduce the main features of crystallographically oriented pores, like uniform pore growth in n-type InP or the formation of domains on n-type GaAs and InP. The model is also capable of reproducing the logarithmic growth law for the pore depth, as well as the pore density oscillations with depth, as recently found.

The formation of crystallographically oriented and current line oriented pores in n-type InP is reviewed and compared to other semiconductors in the light of some new results. A model for the formation of crystallographically oriented pores is presented that reproduced salient features of this pore type rather well. Impedance data together with their model-based evaluation are given and discussed. Some self-organization features of current line oriented pores and their possible relation to self-induced or externally triggered growth mode transitions between the two pore types conclude the paper.

In many areas of research exists a need for single small holes with diameters from a few nm to several µm and large aspect ratios. Ex-isting technologies for that are complex and rather limited. It is shown by a simple proof of principle that suitable single holes or specific arrays of some single holes can be made by first etching a very large number of small and deep holes or pores into semicon-ductors like Si or InP by established electrochemical means, fol-lowed by masking the desired holes and filling all others with, e.g., a metal in a galvanic process. The potential and limitations of this technique are discussed in some detail.

The dynamics of macropore growth in n-type silicon were investigated by in-situ FFT impedance spectroscopy and transient analysis. In particular the response to fast growing pores to current density steps in the context of so-called anti-phase diameter oscillations was investigated. These pore growth mode allows for a very fast growth of deep macropores and could for the first time be stimulated by external current steps.

Surface modification of (100) silicon with methyl groups is analyzed using electrografting and thermal hydrosilation. The surface chemistry is investigated by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), voltammetry and atomic force microscopy (AFM). Surfaces anodically electrografted in methyl Grignard solutions show a smooth topology and improved passivation relative to passivation via hydrosilation. Functionalized surfaces are stable and hinder the formation of oxides up to 45 days after the electrografting as shown in the XPS results.

The electronic properties of hydrogenated and alkyl-grafted silicon surfaces have been investigated by photoluminescence, surface photovoltage and electrochemical capacitance measurements, which are sensitive methods for monitoring the presence of electronic defects. On p-type silicon, the electronic quality of the interface was found to depend critically on the surface preparation and was studied with special care. The thermal grafting of one monolayer of linear organic chains on atomically flat silicon allows the formation of stable alkyl-grafted p-Si surfaces, exhibiting a very low density of recombination centers comparable to those measured on hydrogenated silicon surfaces. Photoluminescence measurements show that the high electronic quality of the grafted surfaces is preserved on a month scale in air, indicating a much more efficient long term passivation by comparison with hydrogenated Si surfaces. The stability of the silicon/organic layer interface in aqueous buffer solution has been assessed by in situ photoluminescence and surface photovoltage measurements. Some degradation of the electronic properties was evidenced during exposure in basic solution of pH > 9.

The phase relation between local maxima of photocurrents and those of in-situ Brewster-angle reflectance (BAR) is investigated upon dissolution of silicon photoelectrodes in diluted NH4F. In the region of photocurrent oscillations, charge flow and optical response can be related by a linear equation which explains the observed positive phase shift of the reflectance. In the transition regime, between porous silicon formation and electropolishing, commencing surface oxidation results in a negative phase shift of the reflectance. It is shown that this observation points to a change in the dissolution mechanism of the surface-near region. A step-function, convoluted with the charge flow, is applied to model the optical behavior. This approach is compared to optical multi-layer analysis in which simultaneously increasing sub-surface porosity and surface roughness are considered.

Macroporous semiconductors such as Si and GaAs with ordered pore intervals were fabricated by the site-selective chemical etching of a substrate using patterned Pd-Pt thin film catalyst through self-assembled colloidal spheres as a mask. The obtained macroporous silicon using noble metal catalyst was conical because the pore wall of macropores was chemically dissolved presumably due to the diffusion of positive holes injected at the metal catalyst. In contrast, relatively straight pores with uniform diameter were grown when the concentration of HF was high. With increasing concentration of HF, the etching rate at the pore bottoms in a vertical direction to the Si surface increased, while the etching rate in a lateral direction was suppressed markedly to yield high aspect ratio of pores up to 10. The change in features of macroporous silicon was thought to be involved in the difference in diffusion behavior of injected positive holes at the silicon/metal interface.

The formation of step bunching was observed by atomic force microscopy on n-type Si(111) surfaces during the electrodeposition of noble metals under semiconductor depletion conditions. The surface chemical analysis performed by synchrotron radiation photoelectron spectroscopy (SRPES) indicates the formation of an ultra-thin oxide film along with the topological transformation. Step bunching is interpreted in terms of site-specific etching controlled by the reactivity of kink sites and step edges together with the surface accumulation of holes supplied by the reduction of Pt-chloride complexes via the valence band.

The effect of thermal treatments for 1h at 250{degree sign}C in air or under vacuum on the electronic structure of thick amorphous anodic niobia was characterized by electrochemical impedance, differential admittance (DA) and photocurrent spectroscopy (PCS). The analysis of anodized niobia has revealed that it behaves as a pure dielectric. The thermal treatment in air increases the value of the differential capacitance of the niobia sample. The effect is stronger when the thermal treatment is carried out in vacuum and can be cancelled out by reanodizing the oxide to the initial formation potential. In the case of thermally vacuum-treated sample, a behavior typical of semiconducting amorphous material has been revealed at different frequencies. The PCS measurements were used to derive the optical band gap value of niobia sample and to confirm the location of the flat band potential derived from admittance data.

Novel plasmaless photoresist removal method in gas phase at room temperature has been developed using pure ozone gas which has nearly 100% of concentration. This method has enabled the removal of high dose ion implanted photoresist that had been difficult to remove so far. Conventionally, the temperature rise of 200{degree sign}C or more was necessary in the photoresist removal with the ozone gas to achieve an enough effect. Because the strong reactiveness is due to the oxygen radical generated when the ozone molecules decomposed. However, Popping by the temperature rise becomes a problem in the removal of high dose ion implanted photoresist. Then, in this experiment, ethylene gas was used to control the decomposition of ozone molecule at the room temperature. As a result, it was confirmed that the ashing using ethylene gas and ozone gas was effective to remove the high dose ion implanted photoresist under unheating condition.