Precipitates and defects in silicon co-implanted with helium and oxygen

Nano-bubbles or voids introduced by He implantation before the oxygen implantation collect oxygen and increase the oxygen content in the sample. Furthermore, nano-bubbles or voids can trap Si interstitials to decrease the dislocations at the edge of precipitates. The density and shape of precipitates formed in the initial stage of the separation-by-implanted-oxygen process are related to the size and density of He-induced vacancy-type defects (nano-bubbles and voids). A high density of nano-bubbles is more efficient in gettering than that of a low density of voids.     

低剂量SOI圆片的无损电学表征测试

通过应用一种新的模型来进行电学测试和参数提取，可以获取SIMOX（离子束注入隔离氧化层）SOI圆片的上界面和下界面的界面态参数以及埋氧层的质量参数，传统的MOS电容结构测试电学特性应用到SOI圆片是有其局限性的，在本实验中直接利用SOI圆片的SIS（Silicon-Insulator-Silicon)结构，将SOI圆片的无损电学表征方法应用到实际的表征当中去，实验采用自行制备的低剂量超薄SIMOXSOI圆片，得到比较可靠的实验结果。     

0.8μm SOI CMOS抗辐射加固工艺辐射效应研究

采用抗辐射0.8μm SOI CMOS加固技术,研制了抗辐射SOI CMOS器件和电路。利用Co60γ射线源对器件和电路的总剂量辐射效应进行了研究。对比抗辐射加固工艺前后器件的Id-Vg曲线以及前栅、背栅阈值随辐射总剂量的变化关系,得到1 Mrad(Si)总剂量辐射下器件前栅阈值电压漂移小于0.15 V。最后对加固和非加固的电路静态电流、动态电流、功能随辐射总剂量的变化情况进行了研究,结果表明抗辐射加固工艺制造的电路抗总剂量辐射性能达到500 krad(Si)。     

Nucleation, growth and retrogrowth of oxidation induced stacking faults in thin silicon-on-insulator

The nucleation, growth, and retrogrowth of stacking faults were investigated for thermally oxidized silicon-on-insulator substrates formed by the separation by implanted oxygen (SIMOX) method. It has been observed that for high oxidation temperatures (T >1150°C) oxidation induced stacking faults (OISFs) undergo a retrogrowth (shrinkage) process at noticeably lower temperatures than in bulk silicon. The retrogrowth process in thin film SIMOX substrates starts at approximately 1190°C for the 2 h thermal oxidations. In this paper, a model for the retrogrowth process is proposed based on the assumption that at high oxidation temperatures vacancies may be injected from the thermal oxide/top silicon interface. We suggest that the vacancy injection reduces the self-interstitial supersaturation and as a direct consequence, attenuates the OISF growth. We also propose that the self-interstitial supersaturation is reduced through point defect recombination inside the silicon overlayer and at the top-silicon/buried-oxide interface where a high density of steps and kink sites are found.     

应用于深亚微米DSOI器件的埋氧层的制备

利用低剂量、低能量的SIMOX（separation by implanted oxygen）图形化技术实现了深亚微米间隔埋氧层的制备．在二氧化硅掩膜尺寸为172nm的情况下，可以得到间隔为180nm的埋氧层．通过TEM（transmission electron microscope）观察发现埋层形貌完整、界面陡峭、无硅岛及其他缺陷．该结果为DSOI（dain/source on insulator）器件向更小尺寸发展奠定了工艺基础．     

基于SIMOX技术的高温压力传感器研制

应用氧离子注入 (Separation by Implantation of Oxygen) SIMOX技术 ,制作适合于高温环境条件下的固态压阻式硅隔离 (SOI)压力敏感元件。采用了一种新型梁膜结合封装工艺 ,有效地解决了被测压力高温冲击问题 ,可应用于航空、航天发动机等恶劣环境下的压力测量。     

Radiation hardness improvement of separation-by-implantation-of-oxygen/silicon-on-insulator material by nitrogen ion implantation

In our work, nitrogen ions were implanted into separation-by-implantation-of-oxygen (SIMOX) wafers to improve the radiation hardness of the SIMOX material. The experiments of secondary ion mass spectroscopy (SIMS) analysis showed that some nitrogen ions were distributed in the buried oxide layers and some others were collected at the Si/SiO₂ interface after annealing. The results of electron paramagnetic resonance (EPR) suggested the density of the defects in the nitrided samples changed with different nitrogen ion implantation energies. Semiconductor-insulator-semiconductor (SIS) capacitors were made on the materials, and capacitance-voltage (C-V) measurements were carried out to confirm the results. The super total dose radiation tolerance of the materials was verified by the small increase of the drain leakage current of the metal-oxide-semiconductor field effect transistor with n-channel (NMOSFETs) fabricated on the materials before and after total dose irradiation. The optimum implantation energy was also determined.     

薄膜SIMOX顶层单晶硅位错的研究

通过超声搅拌的增强化学腐蚀，结合普通的光学显微镜研究不同制备参数的形成的ＳＩＭＯＸ材料顶层单晶硅的位错缺陷，讨论了位错密度同ＳＩＭＯＸ制备工艺的关系。     

全耗尽CMOS／SIMOX器件研制

在表层硅厚度为１８０ｕｍ的ＳＩＭＯＸ材料上，用局部增强氧化隔离等工艺研制了沟道长度为２．５μｍ的全耗尽ＣＭＯＳ／ＳＩＭＯＸ器件。该工艺对边缘漏电的抑制及全耗尽结构对背沟漏电的抑制降低了器件的整体漏电水平，使ＰＭＣＯＳ和ＮＭＯＳ的漏电分别达到３．Ｏ×１０－１１Ａ／μｍ和２．２×１０－１０Ａ／μｍ。５Ｖ时，例相器的平均延迟时间达６ｎｓ。     

薄膜全耗尽CMOS／SOI—下一代超高速Si IC主流工艺

本文较为详细地分析了薄膜全耗尽ＣＭＯＳ／ＳＯＩ技术的优势和国内外ＴＦ ＣＭＯＳ／ＳＯＩ器件和电路的发展状况，讨论了ＳＯＩ技术今后发展的方向，得出了全耗尽ＣＭＯＳ／ＳＯＩ成为下一代超高速硅集成电路主流工艺的结论。