Papers by Author: Shi Xing Jia

Abstract: We report our efforts towards designing and fabricating capacitive microaccelerometers with flat bottom surfaces free from the notching effects of Deep Reactive Ion Etching (DRIE) based on SOI process. The substrate layer under the device structure is etched and a metal film is deposited to the backside of moving structure for protecting the bottom surfaces so that the stiction problem and notching effects are avoided. The test results demonstrate that SOI accelerometers have been released successfully. The measured sensitivity is 169.1mV/g and the linearity of output is within 0.202%.

Abstract: The study is performed to implement the Gold-Gold thermocompression bonding for the wafer-level packaging of MEMS chips. Numerous experimental attempts have been carried out to select the metal film adhesive to avoid the Au-Si melt together and optimize bonding processes to intensify the Au-Au eutectic bonding. Finally the results display that the eutectic bonding of the gold-gold are arrived as electrical as well as mechanical interconnection of the MEMS structure and as seal as well as bonding intension.

Abstract: A method of fabrication of micro via-hole by wet-etching of Pyrex glass is presented in the paper. The through holes with double funnel-shape have been fabricated attribute to isotropic etching. Furthermore, the funnel-shape holes are advantageous to the joint sealing and have been applied to fabricate microfluid chips. The results show that the proportioning of corrosion solution is HF:HCl:H2O=3:6:10, and the corrosion rate is about 0.67um/min, the diameter of the holes on the both-side of the wafer is only 750 um, the middle ones are 300um

Abstract: This paper presents a kind of fine polishing technique that adopts three-step polishing procedure and keeping-wafer-wet method. In order to remove the damaged layer created by lapping process or improve surface condition of silicon wafer, polishing process is needed. In this paper, techniques of improving the surface roughness of silicon are studied, three different polishing processes are presented, and optimum condition has been attained. Experiments of Si-Si bonding are also performed, and results show that after polishing ends, keeping surface of wafer wet is necessary to avoid slurry agglomerating.

Abstract: We report our efforts towards fabricating nanomechanical resonators patterned by optical lithography in silicon nitride. Optical lithography has advantages of low cost and high efficiency over electron-beam lithography. Double clamped beam resonators with thickness 150nm, length and lateral dimensions 20um, 800nm have been designed. Through utilizing reactive ion etching and controlling gas flow, reaction time of CF4 and O2 plasma and power of the upper and lower electrode, nanomechanical resonators with lateral dimensions within 200nm are demonstrated.