A novel method based on electromagnetic wave (EW) was firstly proposed to dry photoresist with high aspect ratio after electron beam lithography. This method used EW to penetrate photoresist and heat the water stored between resist patterns directly, then the water evaporated with absorbing energy of EW. An array of 15,625 pillars and lines with 14.9 nm width of aspect ratio 13 and 17 respectively were dried successfully. By analyzing the heating mechanism, we demonstrated that the EW can decrease surface tension of water effectively and may be applicable for cleaning via hole and the inner wall of carbon nanotubes.

A substrate-free optical readout focal plane array (FPA) operating in 8–12 μm with a heat sink structure (HSS) was fabricated and its performance was tested. The temperature distribution of the FPA with an HSS investigated by using a commercial FLIR IR camera shows excellent uniformity. The thermal cross-talk effect existing in traditional substrate-free FPAs was eliminated effectively. The heat sink is fabricated successfully by electroplating copper, which provides high thermal capacity and high thermal conductivity, on the frame of substrate-free FPA. The FPA was tested in the optical-readout system, the results show that the response and NETD are 13.6 grey/K (F / # = 0.8) and 588 mK, respectively.

Micro-devices with a bi-material-cantilever (BMC) commonly suffer initial curvature due to the mismatch of residual stress. Traditional corrective methods to reduce the residual stress mismatch generally involve the development of different material deposition recipes. In this paper, a new method for reducing residual stress mismatch in a BMC is proposed based on various previously developed deposition recipes. An initial material film is deposited using two or more developed deposition recipes. This first film is designed to introduce a stepped stress gradient, which is then balanced by overlapping a second material film on the first and using appropriate deposition recipes to form a nearly stress-balanced structure. A theoretical model is proposed based on both the moment balance principle and total equal strain at the interface of two adjacent layers. Experimental results and analytical models suggest that the proposed method is effective in producing multi-layer micro cantilevers that display balanced residual stresses. The method provides a generic solution to the problem of mismatched initial stresses which universally exists in micro-electro-mechanical systems (MEMS) devices based on a BMC. Moreover, the method can be incorporated into a MEMS design automation package for efficient design of various multiple material layer devices from MEMS material library and developed deposition recipes.

The spectroscopy is the ultimate way for chemical analysis. This paper mainly describes the idea of an air-sensitive sensor based on MEMS technology, and more over, a photonic crystal (PC) beam splitter was designed, which can achieve high resolution beam steering, and this improves the resolution of the sensor. The paper offers a new idea and lays the foundation for the novel beam splitter that applied to many optical systems.

A novel wet vapor photoresist stripping technology is developed as an alternative to dry plasma ashing and wet stripping. Experiments using this technology to strip hard baked SU-8 photoresist, aurum and chromium film are carried out. Then the images of stripping results are shown and the mechanism is analyzed and discussed. The most striking result of this experiment is that the spraying mixture of steam and water droplets can strip photoresist and even metal film with ease.

The multi-SCCO2 (supercritical carbon dioxide) release and dry process based on our specialized SCCO2 semiconductor process equipment is investigated and the releasing mechanism is discussed. The experiment results show that stuck cantilever beams were held up again under SCCO2 high pressure treatment and the repeatability of this process is nearly 100%.

A novel electromagnetic push-pull RF MEMS switch was proposed.In order to solve the problems caused by traditional electrostatic cantilever RF MEMS switches,such as high actuation voltage and low recovery force,a new push-pull structure was designed to reduce the actuation voltage(current)and increase the isolation.The designed RF MEMS switch realized the SPDT function.The beam distortion induced by the residual stresses in the cantilever beam was solved due to the single crystalline silicon beam without stress.The dimension of the switch was designed based on theoretical analysis and Finite Element Analysis(FEA).10 μm displacement at the free end of the single crystalline silicon beam was obtained at dB/dz=100 T/m magnetic-induction gradient of the outside permanent magnet and 100 mA actuation current,satis-fying the requirement of switch driving.The microfabrication processes of the designed switches were given.The test of S -parameters shows that the isolation is -40 dB at 10 GHz.

The multi-SCCO2 (supercritical carbon dioxide) release and dry process based on our specialized SCCO2 semiconductor process equipment is investigated and the releasing mechanism is discussed. The experiment results show that stuck cantilever beams were held up again under SCCO2 high pressure treatment and the repeatability of this process is nearly 100%.

简要回顾了传统RCA清洗工艺的历史背景和清洗原理,介绍了RCA清洗随着工艺节点减小存在的局限性。在此基础上,阐述了以超临界二氧化碳（SCCO2）为媒质的新型清洗工艺,该工艺流程可以同时实现超临界流体清洗和干燥。结合自主研发的绿色环保二氧化碳超临界半导体清洗设备,论述了利用SCCO2对Si片进行无损伤清洗的工艺原理和工艺流程。分析了近年来国内外对SCCO2清洗的研究进展,展示了其在清洗方面的巨大潜力以及在微电子行业应用中的有效性和优越性,其研究成果有利于推动下一代清洗工艺的发展。

In wafer cleaning techniques,conventional cleaning mediums are difficult to go deep into tiny trenches on IC chips due to the surface tension of aqua.The unavoidable desiccation process after wet cleaning would bring granule adsorption and structure distortion or invalidation because of the surface tension caused by the gas/liquid interface.Cleaning technology based on supercritical carbon dioxide is the best way to conquer the mentioned embarrassments.Supercritical carbon dioxide green IC cleaning apparatus could implement zero-surface tension cleaning/desiccation,and sacrificial layer release.The apparatus,a kind of green semiconductor manufacturing equipment,is a low-cost,high-yield rate,and carbon dioxide-cycle apparatus.

A novel MEMS/CMOS compatible gas sensor based on spectroscopy analysis,which is fabricated on a (110) silicon wafer,is proposed.Its main principle,structure,and fabrications are introduced in detail.The gas sensor gains high sensitivity and selectivity but has low power consumption,and it should detect the grads of gas concentration for the mentioned advantages.

The simulation,design and fabrication of a seesaw type radio-frequency microelectromechanical system switch were proposed.The switch utilizes the single crystal silicon as the movable parts to realize flexible restoring forces and improve the stress deformation of the film.The seesaw structure resolves the problem of a small contacting force in the traditional electrostatic switch and makes the restoring force adjustable by controlling the fulcrum.It can be used to lower the actuation voltage with the high isolation maintaining and the simulated switching voltage is 5-10 V.The switch can be directly applied to radio-frequency communications channel selection with its single pole double throw(SPDT) feature.Finally,the results and discussion of the microwave measurement on coplanar waveguide(CPW) structure were presented.

Conventional IC cleaning technology could hardly provide effective wafer with subtle microstructure, but this problem would be solved when the cleaning media is substituted by supercritical point carbon dioxide (SCCO2). SCCO2 is characterized as no surface tension, low viscosity, and high diffusivity, no noxious and recyclable use. This new cleaning technology would be widely used in IC technology due to the mentioned advantages. A green SCCO2 cleaning apparatus is proposed in this paper, and the apparatus could implement supercritical cleanout and desiccation with recyclable CO2.