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.
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.
In this paper, numerical analysis was investigated for the double-clad fiber lasers and experimental study on the Yb<sup>3+</sup>-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 Yb<sup>3+</sup>-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.
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.
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.