SBIR Phase I: Starter Wafers for Diamond MEMS Fabrication

这个小型企业创新研究第一阶段项目将确定在二氧化硅和硅(绝缘体上金刚石，DOI)上以类似于绝缘体上硅(SOI)晶片的策略，制造由超纳米晶金刚石(UNCD)组成的铸造级MEMS启动器晶片的可行性。研究团队已经解决了厚度均匀、sp3/sp2比均匀、颗粒尺寸均匀、附着力和粗糙度(30 Nm RMS)的问题，但仍然存在应力水平、颗粒密度(102 cm-2颗粒1um，主要是由于非洁净室加工)和有限的声速均匀(14-16 KM/S)的问题。第一阶段将1)实施一种新的应力降低方法，将应力降至-50至+100 Mpa，并通过后续热处理(利用LPCVD沉积氧化物和氮化物层，PECVD)证明所产生的能级是守恒的；2)证明器件层上的颗粒密度可降至10/cm2以下(对于尺寸为1微米的颗粒)，而背面污染可以通过特殊的播种条件和清洗来消除；3)优化沉积条件，以10%的置信度在4英寸和6英寸直径的DOI晶片上将声速带到16公里/S的范围。UNCD通过其出众的硬度、杨氏模数、韧性、声速、平整度、均匀性、生物兼容性和可调的导电性，证明了其在MEMS组件方面的优势。钻石MEMS产品的商业化受制于有限的(高)质量钻石生产能力，终端用户对钻石缺乏经验，以及对播种过程(钻石生长的先驱)可能导致污染问题的担忧。目前的DOI产品面向不同层次的用户(小公司、铸造厂、研究中心)，他们希望进入钻石MEMS领域。钻石MEMS在RF-MEMS(谐振器、过滤器、无线通信和信息技术振荡器)、生物可植入芯片(人工视网膜、人工耳蜗、可植入ID芯片)、电子和材料研究(AFM探头、数据存储设备、X射线和电子光学)、传感器(声表面波传感器、振动悬臂传感器等)方面具有巨大的潜力。

This Small Business Innovation Research Phase I project will determine the feasibility of making foundry-quality MEMS starter wafers composed of ultrananocrystalline diamond (UNCD) on SiO2 and on Si (diamond-on-insulator, DOI) in a strategy similar to silicon-on-insulator (SOI) wafers. The research team has solved problems of thickness uniformity, sp3/sp2 ratio uniformity, grain size uniformity, adhesion, and roughness (30 nm rms), but problems remain with the stress level, particle density (102 cm-2 particles 1 um mainly due to non-clean room processing), and limited uniformity of the acoustic velocity (14-16 km/s). Phase 1 will 1) implement a novel method for stress reduction to bring it down to -50 to + 100 MPa and prove the resulting level is conserved through subsequent thermal processing (deposition of oxide and nitride layers by LPCVD, PECVD), 2) prove that particle density on the device layer can be reduced to under 10/cm2 (for particles of size 1 um) while backside contamination can be eliminated by special seeding conditions and cleaning, and 3) optimize the deposition conditions to bring the acoustic velocity to the 16 km/s range with a 10% confidence level on 4" and 6 " diameter DOI wafers. UNCD has proven its advantages for MEMS components through its exceptional hardness, Young's modulus, toughness, acoustic velocity, smoothness, uniformity, bio-compatibility, and tunable conductivity. The commercialization of diamond MEMS products is inhibited by limited (high) quality diamond production capabilities, little experience with diamond by end users, and concerns that the seeding process (precursor of diamond growth) may lead to contamination issues. The present DOI product targets users at various levels (small companies, foundries, research centers) who want to enter the diamond MEMS realm. Diamond MEMS has great potential in RF-MEMS (resonators, filters, oscillators for wireless communication and information technology), bio-implantable chips (artificial retina, cochlear implants, implantable ID chips), electronics and material research (AFM probes, data storage devices, x-ray and electron optics), sensors (SAW sensors, vibrating cantilever sensors, etc).