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ZnO is the most SURPLVLQJPDWHULDOIRUWKHDSSOLFDWLRQRIDQXOWUDYLROHW 89 GHWHFWRU . However the shortage of p-type ZnO becomes the biggest blockage for fabricating ZnO-based semiconductor device. In this paper, following experiments had been done: Firstly, the zinc nitride powders were synthesized through the nitridation reaction of Zn power with NH 3, and the optimized synthesis temperature was at 600 . Next, the zinc nitride powder was fabricated into a zinc nitride sputtering target by a single pressing process. Th irdly a thin layer of zinc nitride film was formed on silicon and quartz substrate using magnetron sputtering method. Fourthly, the zinc nitride film was oxidized into p-type ZnO, and the best optimized temperature for forming p-type ZnO by oxidizing Zn 3 N 2 thin film was at 500 . Lastly, the ohmic contact for p-ZnO and ZnO based detector were fabricated. It was found Al and Ni/Au showed ohmic contact properties to n- Si and p-ZnO, respectively, and the p-Zn O/n-Si junction as a UV detector was feasible. Keywords: Znic nitride, p-type ZnO, ohmic contace, UV Detector

The MEMS silicon-micro-machining is the main MEMS technology, which includes the surface-silicon-micro-machining and the bulk-silicon-micro-machining technology; however the bulk-silicon micro-machining technology has a wide application. In this paper, the formation procession of electron multiplier on n-type Silicon substrate by bulk-silicon-micro-machining technology was investigated. A series of electrochemical etching experiments and tests were carried out in three poles electrobath system using HF electrolyte with different concentration. The rate of photoelectrochemical etching on the macropore depends on a few technological parameters, such as doping concentration, operating bias, illumination intensity of the light, HF concentration, and so on. It was found that the formation possibility of the macropore array is directly correlated with crystal orientation of n-type Silicon substrate.

In this paper, the noise and optical aberration which were two controllable factors that affect the image quality in the single-proximity-focusing x-ray image-intensifier were studied. By decreasing the electron gain of microchannel plate (MCP), the noise of the x-ray image-intensifier can be decreased. The optimal operating condition for the image intensifier and the CCD were also investigated. Based on this investigation, the flash-noise of the x-ray image-intensifier can be decreased and the brightness of the image can be improved. At the end of the paper, some results on the image-capturing of the cool CCD with low noise were presented.

Microsphere plate (MSP) is a new type of electron multiplier device. It is similar to the traditional microchannel plate (MCP) in dimensions and model of operation. Compared with the MCP electron multiplier, the MSP has some unique characteristics such as a high electron gain, without ion feedback and easy to be fabricated, thus it is widely used in the fields of imaging and detecting. However, there are some key technologies to fabricate a satisfied MSP. In this paper, the whole fabrication process of MSP was introduced and some of major processes such as the formation of glass beads, the sintering of MSP body, and the formation of dynode and electrodes were specially discussed. At the end of the paper, the optimal processed for the fabrication of MSP was given.

The stopping power of ion barrier films (IBFs) of Microchannel Plate (MCP) in Generation III image tubes for incident positive ions was described in this paper. Nuclear Stopping Power, Electronic Stopping Power and Mean Range were introduced. These concepts were analyzed and discussed, combined with Tomas-Fermi shielding potential. The results of a Monte Carlo simulation on Nuclear Stopping Power, Electronic Stopping Power and Mean Range were also presented when the ions with different energies were perpendicularly incident to Al 2 O 3 and SiO 2 films. The results indicate that the stopping power of Al 2 O 3 film is stronger than that of SiO 2 , and the selection of Al 2 O 3 is reasonable and feasible.

The fabrication of ion barrier film on microchannel plate (MCP) was introduced. The experimental system for high-temperature vacuum baking on MCP and technological condition were given. The measurement on the electrical properties, the dead-voltage and other parameters of MCP with an ion barrier film were shown. The changes before and after high-temperature vacuum baking were also investigated for the MCP with ion barrier film. By analysis and discussion, it was concluded that high-temperature vacuum baking caused the film's thickness changed, the dead-voltage decreased, and the electron gain decreased with the increase of the film's thickness for the MCP with an ion barrier film.

The photomultiplier tube (PMT) that can work in different wavelength is an important detector device in remote sense technology. Microsphere plate using glass beads 50to 70μm in diameter sintered together is the core component of the microsphere plate photomultiplier tube It is a novel two-dimension electron multiplier. The electrons gain for a single plate is about 1017 and do not have the phenomenon of ion-feedback. Furthermore the fabrication process is very easy. In this paper, much interest was put on the microsphere plate photomultiplier tube. Based on the analyses from the theory and the experiment result, we point out the key technology for fabricating PMT is how to obtain glass beads with narrow range in diameter and how to sinter the glass beads with a sufficient pylome. Factors affect the gradating technology and sintering process along with the solution to them is presented. In the last, the structure scheme and technological characteristic for fabricating microsphere plate photomultiplier tube were given. The pulse rising-time of MSP-PMT is below 400ps suitable to the detection of high-speed pulse. As easy to be fabricated and has great advantage over MCP multiplier in the ratio of performance to price, the microsphere plate photomultiplier tube is a promising dim-light detector.

Computer Generation Image (CGI) system is main part of the flight simulator. Usually, the Image Generation Workstation to be used in CGI system is very expensive. This paper presents a low cost CGI system based on PC and we use it to develop a flight simulator, which has a 3 channels display system with wide field-of-view (horizontal 240°× vertical 60°). First, the paper discusses the architectural principles of CGI system and provides a CGI system based on PC. Second, a type of 3 channels display system is described. The display system is designed in folded flat screen using rear project curtain. Adjacent screen shapes a 100° corner and each channel provides 80°×60° field-of-view. Furthermore, some key technologies, such as image connection, channels synchronization and channels communication, are discussed in detail. At the end of paper, a flight simulator with 3 channels visual scene is described and it is successfully implemented in training pilot. PC-Based CGI system also can be applied to a lot of fields including multimedia commerce, medical media databases visualization, CAD/CAM, scientific computing visualization, and entertainment.

In this paper, numerical analysis was investigated for the double-clad fiber lasers and experimental study on the Yb3+-doped double-clad fiber lasers was performed. The results shown that the output power increased monotonically with absorbed power, and in lossy cavity the output power is less than in the lossless cavity. The output power decreases for the lossy fiber with the reflectivity of output coupler. There was an optimum fiber length to reach a maximum output and the optimum length was mainly dependent on the loss coefficient. In experiment we obtained an output power of 21.6W, slope efficiency of 54% by using Yb3+-doped double-clad fiber and 40W LD pump source.

The MCP ion barrier film in low-light-level imaging tube and its process techniques were introduced in this paper. The electron transmittance of this film was studied. The results of half field-of-view testing comparisons and the concept of dead voltage were presented. The dead voltage curve and the relation between dead voltage and thickness of film were tested. The composition of film was analyzed by XPS.

Theoretical foundation and principle programmer will be studied in this paper that special photosensitive Si-PSD (Si-Position Sensitive Detector) is rebuilt into electron bombardment mode device, which is based on minimal weak light detecting technical demands and exciting principle of high-energy electronic beam acting on silicon semiconductor. At the same time we will bring forward new concept device of electron bombardment mode PSD. According to the theoretical foundation and principle programmer, we present the practical measurement result that semiconductor gain of electron bombardment mode device is obtained. When incident electron energy is more than 4KeV, then obtained more than 103 gain. We have produced high-sensitivity photon-counting imaging detector (MCP-PSD tube) with 108~109 gain, which combined the research of microchannel plate (MCP) cascade applications with electron bombardment mode device. This paper also will present the substantial photograph of electron bombardment mode PSD device and MCP-PSD tube. Finally we will bring forward prospect realizing detection of minimal weak light photon-counting imaging.

In this paper, proximity focus x-ray intensifier and corresponding Lixiscope system at home and abroad are introduced. The technical parameters and characteristics are given. The technical ways to improve Lixiscope and the application prospect are offered.

The formation of deep macropore array of p-type Silicon in HF electrolyte has been investigated. Then a series of electrochemical etching experiments and tests were carried out in three poles electrobath using different concentration HF electrolyte. HF concentration is a very important factor that determined whether electrochemical reaction was accomplished or not. By means of theoretical analysis and investigation, it is generally assumed that etching proceeds through sequential reaction of Si-H groups with F- to form Si-X, which determined whether electrochemical etching reaction was carried out or not. The electrochemical etching of p-type Silicon macropore array in aqueous fluoride solutions is satisfied with economic requirements for costs of fabricating deep macropores. The consequences are benefit to Silicon electrochemical deep macropore array etching technology.

This paper reports on a silicon micro-hole arrays (Si-MHA) prepared by Inductively Coupled Plasma (ICP) etching, a dry etching method. By ICP etcher, we carried out several experimental researches and process exploration for micromachining Si-MHA. The mechanism of lateral etching, sidewall passivation, gas micro-transport and some process parameters in Si-MHA micromachining, such as gas switching time, flow rate, etching rate, were analyzed. The footing effect, lag effect, longitudinal strips and RIE grass effect occurred in the ICP etching process were also studied. These process problems had reappeared in the micro-hole arrays process though these problems had be solved in the field of integrated circuits process and microelectromechanical system (MEMS). The study results reported here had demonstrated a Si-MHA that the diameter was 15 μm, the center distance 30 μm, and the depth 240 μm prepared by ICP, and had led the author to believe that the deep pore structure and the deep trench with high aspect ratio were very different in etching process. The former is a closed structure for the gas transport, and the latter is an open structure, so the process of deep hole structure is a puzzle in micromachining and MEMS technology.

A New type of X-ray imaging intensifier was studied and developed. This intensifier combined with a little focal spot X-ray tube and a miniature high voltage power supply. Our product had performances of small volume, light weight, portable, high luminosity, Low X-ray radiation density and real-time imaging in daylight. The Lixiscope had also characteristics of simple structure, simple process, long lifetime, low cost and easy to application and promotion. The qualification of the imaging tube and the system: field range 50 mm, brightness 15 - 20 Cd/m2, screen resolution greater than or equal to 5 lp/mm, X-ray tube current 0.05-0.10 mA, target voltage 40 - 60 KV (continuous adjustable), DC/AC available, portable 2.5 Kg. To improve the X-ray imaging intensifier, we adopted several technologies as below. The little focal spot X-ray tube (0.5 mm2) and X-ray collimator was used to increase the resolution, maximum 10 lp/mm, the fiber faceplate or light cone output window to increase brightness and field range, nd the large area and high resolution MCP to increase field range. So, the developed X-ray imaging intensifier had found the widely application.

Microchannel plate (MCP) is a device of two-dimension array electron multiplier. The detection ability to 40 - 60 KeV X-ray for MCP was increased by coating the halide such as CsI, CsBr and KBr on input plate of MCP, that forming a reflection X-ray sensitive film in the channel with depth of 2 - 3 times of diameter below the input plate. Experiment results show that the output response of MCP with variable density structure CsI to X-ray is about 5 - 6 times higher than that with constant density structure, and of one order of magnitude stronger than that without coating the film. Comparatively, the output response of MCP with CsI sensing film is best, CsBr medium and KBr bad. The response characteristics of MCP with CsI to X-ray related to film materials, structure, component distribution and process. Several experiment curves denoted the response characteristics to X-ray at different target voltage and current. The results basically accorded with the theory about quantum detection efficiency of reflection X-ray cathode. This new MCP reflection X-ray sensitive film of variable density halide has been successfully applied in X-ray imaging detecting devices. The corresponding detection system will find widely and potential applications in the field of medical diagnosis, nondestructive evaluation and security inspection, etc.

This paper reports on a silicon mcrochannel arrays prepared based on bulk-micromachining technology, dry etching technology and electrochemical process respectively. In dry etching, a silicon microchannel plate (Si-MCP), with 15-30 aspect ratio of the microchannel, 6-20 µm, 6-8 µm space and 150-300µm depth, were prepared by Inductively Coupled Plasma (ICP). The phenomenon ofplasma etching lag and the morphology ofthe microchannel array in dry processing were analyzed and discussed.In wet process, both p-type and n-type silicon was selected as the substrate for microchannel arrays. A inducing pit arrays was first prepared by oxidation, lithography, KOH etching, and then a square channel arrays that has 4 µm length of side and 2 µm space were formed by electrochemical etching in hydrofluoric acid in three poles electrolyzing cell, which can yield straight holes with high aspect ratio. The electrochemical mechanism of silicon anisotropy etching, the parameters of three pole electrolyzing cell, and the inducing pit and channel morphology were investigated and discussed. The results shows that the high aspect ratio of silicon microchannel arrays can be made by both dry and wet etching processes. The ICP process yield a microchannel arrays with uneven, re-entrant, notched and ripples surface within the channel. The electrochemical process for silicon microchannel arrays has lower cost than ICP process.

A silicon microchannel plate (Si-MCP), with 15-25 aspect ratio of the microchannel, 6-20 microns diameter and 6-8 microns space, was prepared by Inductively Coupled Plasma (ICP) and LPCVD. The inner surface topography of microchannel was surveyed, the bulk resistance 7.3 mega ohm and electron gain 110 of MCP were tested by ultraviolet optoelectronic method. The plasma-etching lag in processing the microchannel array was analyzed and discussed. Finally, we compared the electron gain of silicon microchannel plate with traditional glass one. Our work proved the feasibility of making Si-MCP by microfabrication and semiconductor process.

A new technology and method preparing ions barrier film on the input face of multi-hole substratum, MCP, without carbon pollution were studied and introduced in this paper. The composition of the film and the performance of MCP coated with ion barrier film were tested by XPS and UV photoelectric emission method. The new process made the carbon content largely decrease in the film, and the characteristics of MCP unmodified.

The photoemission characteristics of aluminum (Al) and gold (Au) thin film photoelectric cathodes were studied. The metallic cathode stability after exposed to air was investigated. The results of the experiments and study on its photoemission were given, and the application prospect of surface emitter in near UV region was proposed.

In this paper, the characteristics and applications of the window materials within the range of UV, cathode in near UV, and the analogue imaging system of the double-proximity type in near UV with the Au thin film cathodes were introduced.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper introduces the materials and structure as well as the forming method of ultrathin films for ion-preventative feedback. The characteristics and measuring results are given. In the meantime, preliminary analysis and discussion are carried out.

This paper introduces the principle and the electron response characteristics of PSD, describes the structure feature of the new type MCP-PSD photon-counting tube. The following rules of the series working of MCP is expounded. Finally, the application prospect of the MCP-PSD devices have been pointed out.

This paper introduces a new structure X-ray cathode consisting of new structure haloid coating integrated on the input surface of MCP that is applied in single proximity x-ray intensifier. The current response characteristics of different structure CsI, CsBr and KBr cathodes are compared. The conclusion of excellent output response of the dense-loose-dense three-layer new structure CsI Cathode in the energy range 40 - 50 Kev is obtained.

This paper describes the characteristics of long life microchannel plate (L2MCP), analyzes the reason why the lifetime of common MCP becomes short, gives the principle and technique of the new method which can lengthen the operating lifetime of MCP, and introduces an electron scrubbing experiment, UV-photoelectric testing method, and the results. Finally, the advantage and the application prospect of the technology are pointed out.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.