ZnO:Al films with a thickness of about 880nm were deposited by magnetron sputtering. The glass substrate was not heated neither before during nor after the deposition. Subsequently the deposited layers were treated by flash lamp annealing (FLA) at 1.3 ms. Using this method, the resistivity of the ZnO:Al films was decreased by a factor of two, down to 1.0 x 10-3 Ωcm. These results are in good agreement with results reported from rapid thermal processing or furnace annealing treatments. Despite the very short annealing time of only 1.3 ms not only the resistivity but also the transmittance in the UV and the blue range were considerably improved.

Using ion implantation different rare earth luminescent centers (Gd3+, Tb3+, Eu3+, Ce3+, Tm3+, Er3+) were incorporated into the silicon dioxide layer of a purpose-designed Metal Oxide Silicon (MOS) capacitor with advanced electrical performance, further called a MOS-light emitting device (MOSLED). The silicon dioxide layer did not contain silicon nanoclusters. Efficient electroluminescence was obtained from UV to infrared with a transparent top electrode made of indium-tin oxide. The electroluminescence properties were studied with respect to the luminescence spectra, decay time, impact excitation, cross relaxation (Tb3+), and power efficiency. Top values of the efficiency of 0.3 % corresponding to external quantum efficiencies well above the percent range were reached. The electrical properties of these devices such as current-voltage and charge trapping characteristics, were also evaluated. Moreover, we demonstrate photo- and electroluminescence in correlation to charge trapping characteristics for Er-rich MOSLEDs with a varying silicon cluster content. Finally, application aspects to the field of biosensing will be discussed.

The use of flash lamp annealing for processing semiconductor materials is outlined. Specific applications include ultra-shallow junction formation and heteroepitaxial growth of improved quality thin films of cubic silicon carbide. It is demonstrated that flash lamp annealing holds great promise as a technique for fabricating novel devices.

Deep level transient spectroscopy (DLTS) was used to study deep level defects in He-implanted n-type 6H-SiC samples. Low dose He-implantation (fluence ∼2×1011 ions/cm2) has been employed to keep the as-implanted sample conductive so that studying the introduction and the thermal evolution of the defects becomes feasible. A strong broad DLTS peak at 275K-375K (called signal B) and another deep level at EC-0.50eV were observed in the as-implanted sample. The intensity of the peak B was observed to linearly proportional to the logarithm of the filling pulse width, which is a signature for electron capture into a defect related to dislocation. After annealing at 500°C, the intensity of peak was significantly reduced and the remained signal has properties identical to the well known Z1/Z2 deep defects, although it is uncertain whether the Z1/Z2 exist in the as-implanted sample or it is the annealing product of the dislocation-related defect. The E1/E2 defect (EC-0.3/0.4eV) was not presence in the as-implanted sample, but was observed after the 300°C annealing.

The development of novel devices for optical communication and integrated sensor applications is mainly focused on their possible integration into dedicated integrated circuits. The main problem concerning integrated optical systems in silicon technology has always been the realization of a highly efficient silicon-based light emitter which is a key requirement to make a real step into the world of integrated optoelectronics.

One of the most promising approaches to form such a silicon based light emitter is ion beam processing. In this paper we will report on recent results regarding blue-violet (∼400 nm) and infrared (∼1100 nm) electroluminescence (EL) from ion beam synthesized Ge-rich silicon dioxide layer and Boron-implanted pn-junctions in silicon showing remarkable power efficiencies of 0.5 and 0.12%, respectively. The main effort is devoted to the achievement of a deeper insight into the mechanism of the EL.

180 nm thick SiO2 films produced by wet oxidation of (100) Si wafers were implanted at room temperature with 120 keV Ge+ ions at a fluence of 1.2×10 cm-2 in order to allow the formation of Ge nanoparticles upon post implantation thermal annealings within the interval 400°C ≤ T ≤ 900°C. The size and depth distribution of the Ge nanoparticles were characterized by Transmission Electron Microscopy and Rutherford Backscattering Spectrometry. In addition, the room temperature photoluminescence (PL) bands of the nanoparticles system were studied in the regions of the blue-violet and ultra-violet emissions. The mean diameter of the nanoclusters increases from 2.2 nm at 400°C to 5.6 nm at 900°C. Concomitantly, the blue-violet PL intensity increases by a factor of 12 within the same temperature interval. The results are discussed in terms of possible atomic mechanisms involved in the coarsening behavior and leading to the formation of luminescent centers.

Transmission electron microscopy (TEM) was used to investigate Al, Ar, C and Si ionimplanted 4H-SiC epilayers. After the implantation the samples were thermally annealed for 30 minutes at 1700°C. During the annealing process dislocation loops are formed and the generation of such dislocation loops upon annealing, is investigated with respect to dopant electrical activation, peak ion concentration and calculated interstitial/vacancy concentrations. It is concluded that the dislocation loops are generated as the result of a combination of residual damage and excess interstitials generated in a “plus one” (+1) process.

The development of novel devices for optical communication and integrated sensor applications is mainly focused on their possible integration into dedicated integrated circuits. The main problem concerning integrated optical systems in silicon technology has always been the formation of an highly efficient silicon-based light emitter which is a key feature to make a real step into the world of integrated optoelectronics.

One of the most promising approaches to form such a silicon based light emitter is ion beam synthesis. In this paper we will report our recent progress in extracting blue-violet (∼400 nm) electroluminescence (EL) from an ion beam synthesized Ge-rich silicon dioxide layer. The power efficiency of the EL was as high as 0.5 % which is one of the best values ever reported for Si - based light emission. The lifetime of the EL-device can reach several hours without special precautions of stabilizing the EL-active layer against ion or other contamination. Moreover, results are reported dedicated to the investigation of the excitation mechanism of this strong EL.

Nanocluster memories are promising for future non-volatile memory applications. In this work thin SiO2 films were implanted with Ge+ and Si+ and annealed subsequently. Charge storage effects of the MOS capacitors have been studied through I-V and high frequency C-V measurements. Positive voltage pulses lead to a positive flatband voltage shift of the C-V curve. Detrapping by applying negative voltage pulses leads to a negative shift. The achieved programming window using 6 V / 100 ms pulses for Ge based structures is higher than that for Si (2.0 V vs. 0.2 V). However the retention times for Si based memories are longer. For dedicated process parameters microstructural investigations (RBS, XTEM) of Ge+ implanted SiO2 layers showed two bands of clusters, one near the interface SiO2/Si and one in the center of the SiO2 layer.

Two deep levels, located at Ev+0.26eV and Ec-0.44eV, in Al-implanted n-type samples and one at Ev+0.48eV in p-type samples have been observed by the deep level transient spectroscopy. The level of is identified as the shallower aluminum-acceptor. The 1.7 MeV electron-irradiation, used as a probe to distinguish the implantation induced deep-levels, induces at least six electron traps in the n-SiC and one hole-trap in the p-type material. The peak positions of these deep-levels in DLTS spectra are quite different from those induced by Al-implantation. This result suggests that various damages are formed after heavy ion (Al) and light particle (e) irradiation.

Photothermal methods provide a valuable complement to the destructive measurement techniques for the detection of the optimal process conditions in ion beam synthesis of wide band gap semiconductor compounds. In addition to their nondestructive and non contact qualities, they are highly sensitive to changes of thermophysical properties due to structural changes. Analyses have been carried out with (SiC)l-x(AIN)x compounds, formed by ion beam synthesis.

Photoluminescence (PL) and electroluminescence (EL) from Si+- and Ge+-implanted SiO2 layers thermally-grown on a Si substrate were studied. The PL spectra were recorded after annealing at temperatures in the range of 400° to 1200°C. Single-peak PL at 460 nm and doublepeak PL at 420 and 385 nm due to Si+-implanted and Ge+-implanted oxide layers, respectively, reached a maximum following heat treatment at 500°C for 30 min. The EL spectra from the Gerich oxides after annealing at 1000°C correlated very well with the PL signal, and showed a linear dependence on the injection current. The EL emission was strong enough to be readily seen with the naked eye, and the EL efficiency was estimated to be about 5×10−4. High-resolution transmission electron microscopy (HRTEM) analysis showed that the formation of nanocrystals in the implanted oxide layers occurred at annealing temperatures in excess of 800°C. The observed light emission is attributable to the presence of-≡Si-Si≡, ≡Si-Ge≡ and ≡Ge-Ge≡ centres in SiO2.

High-energy, self-ion implantation has been used to form deep gettering layers in Si. Subsequently samples have been contaminated with Cu and subjected to heat treatment. The residual defects act as gettering centres for Cu. The decoration of defects byCu making them detectable by secondary ion mass spectromety analysis. Metastable defect complexes have been detected which, because of their small size, are not directly detectable by other analytical techniques such as transmission electron microscopy and MeV-particle channeling. These defects are probably of interstitial type and have been found mainly midway between the sample and the projected ion range, i.e. around Rp/2. The gettering ability of these small defect complexes may largely exceed that of the post-anneal damage at the projected i.e range, Rp. The results obtained demonstrate that by means of metal gettering the formation, growth and dissolution of very small defect complexes in ion-implanted Si can be studied.

The formation of cavity microstructures in silicon following helium implantation (10 or 40 keV; 1×1015, l×1016 and 5×1016 cm−2) and annealing (800 °C) is investigated by means of Transmission Electron Microscopy (TEM), Rutherford Backscattering Spectrometry and Channeling (RBS/C), and Elastic Recoil Detection (ERD). The processes of cavity nucleation and growth are found to depend critically on the implanted He concentration. For a maximum peak He concentration of about 5×1020 cm−3 the resulting microstructure appears to contain large overpressurized bubbles whose formation cannot be accounted by the conventional gas-release model and bubble-coarsening mechanisms predicting empty cavities. The trapping of Fe and Cu at such cavity regions is studied by Secondary Ion Mass Spectrometry (SIMS).

Metal-Induced-Crystallization (MIC) by the contact of amorphous semiconductors with metals is one of the degradation factors in solar cells. This study has been made on the barrier properties of a ZnO layer between undoped a-SiGe:H and Al metallization films in the structure (001)Si/SiO2/a-SiGe:H/ZnO/Al. Plasma assisted CVD deposition was used to produce a-Si1.xGex:H (x=0 to 1) undoped films over thermally oxidized Si-wafers. There were covered with 500Å and 1000Å thick transparent conductive layers of ZnO. Al and then 1000Å thick films of Al. A set of Al-implanted a-Si, a-Ge, and a-Sio.5Geo.5 films on Si/SiO2 substrates was also prepared to study MIC in an amorphous system with dispersed Al. The structures were annealed in vacuum in the temperature range of 200°C to 400°C for lh. X-ray diffraction studies demonstrated the a-SiGe:H stability against crystallization under ZnO protection up to 400°C. Secondary Ion Mass Spectroscopy didn't reveal any noticeable redistribution of Al inside Al-implanted a-Si:H and a-Si0.5Ge0.5:H samples after annealing at 400°C for lh, but strong Al diffusion was seen in the a-Ge:H layer. Nevertheless, no MIC was observed in any of the Al-implanted a-materials.

New examples of characterization of vacancy-type defects in ion implanted and annealed SiC by the established technique of slow positron implantation spectroscopy are presented. In particular, the estimation of the depths of damaged regions and their change (a) after post-irradiation annealing, or (b) due to variation of substrate temperature during implantation, is addressed.

We studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1.2×1017 W+cm−2 at temperatures between 200°C and 400°C. The influence of implantation temperature on the distribution of W in SiC was investigated and compared to results obtained earlier from room temperature (RT) and 500°C implants. Rutherford backscattering spectrometry (RBS) was employed to study the structure and composition of the implanted layers. Implantation at temperatures between RT and 300°C did not influence the depth distribution of C, Si and W. The W depth profile shows a conventional Gaussian shape. Implanting at higher temperatures led to a more confined W rich layer in the SiC. This confinement is explained by Ostwald ripening which is enabled during implantation at temperatures above 300°C. The depth of the implantation induced damage decreases slightly with increasing implantation temperature, except for 400°C implantation. The amount of damage, however, is significantly reduced only for implantation at 500°C.

Strong blue, red and near-infrared photoluminescence has been observed from Si+-implanted and pulse-annealed SiO2 layers. Raman scattering and high-resolution electron microscopy analyses have revealed a correlation between the structure of the Si inclusions in the SiO2 matrix and the photoluminescence. Structural transformations in the Si-rich SiO2 layers during pulse and furnace annealing have been discussed in terms of the changes in the light emission observed experimentally. Small Si clusters, non-crystalline inclusions and nanocrystals are believed to be the light sources. The blue, red and near-infrared photoluminescence is associated with small complexes of excess Si atoms, non-crystalline Si nanoinclusions and quantum-confined Si nanocrystals, respectively.

SiC is a promising semiconductor material for high-power/high-frequency and hightemperature electronic applications. For selective doping of SiC ion implantation is the only possible process. However, relatively little is known about ion implantation and annealing effects in SiC. Compared to ion implantation into Si there is a number of specific features which have to be considered for successful ion beam processing of SiC. A brief review is given on some aspects of ion implantation in and annealing of SiC. The ion implantation effects in SiC are discussed in direct comparison to Si. The following issues are addressed: ion ranges, radiation damage, amorphization, high temperature implantation, ion beim induced crystallization and surface erosion.

We studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1.2x 1017 WIcm 2 at temperatures between 200°C and 400°C. The influence of implantation temperature on the distribution of W in SiC was investigated and compared to results obtained earlier from room temperature (RT) and 500°C implants. Rutherford backscattering spectrometry (RBS) was employed to study the structure and composition of the implanted layers. Implantation at temperatures between RT and 300°C did not influence the depth distribution of C, Si and W. The W depth profile shows a conventional Gaussian shape. Implanting at higher temperatures led to a more confined W rich layer in the SiC. This confinement is explained by Ostwald ripening which is enabled during implantation at temperatures above 300°C. The depth of the implantation induced damage decreases slightly with increasing implantation temperature, except for 400°C implantation. The amount of damage, however, is significantly reduced only for implantation at 500°C.