Polycrystalline Silicon Micromechanical Beams
Polycrystalline Silicon Micromechanical Beams
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多晶硅微机械梁
DOI：
10.1149/1.2119965
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发表时间：
1983
影响因子：
3.9
通讯作者：
R. Muller
中科院分区：
文献类型：
--
作者：
R. Howe;R. Muller
采用传统的MOS平面工艺，用多晶硅制作了微型悬臂梁和双支承机械梁。制作了厚度为230 nm~2.3/~m，与衬底相隔550 nm~3.5/~m的多晶硅微机械梁，其长度和宽度范围很宽。研究了两种静态力学性能：最大自立长度和梁的挠度与梁厚度的关系。通过在束形成之前对多晶硅进行热处理，这两种特性都得到了改善。多晶硅中不均匀的内应力是导致光束偏转的主要原因，提出了一种利用多晶硅制作悬臂梁和双支承微机械梁的新方法。只需要两个掩蔽步骤，如图1所示。第一步，图1。La，打开生长或沉积在硅片上的氧化层中的窗口。接下来，在第二个掩模步骤中，多晶硅被沉积和等离子刻蚀，留下图的横截面。lb.将晶片浸入缓冲的HF中会去除所有氧化物，削弱多晶硅层并产生悬臂梁，如图所示。LC.双支承梁，图3。TD是通过在光束的另一端包括第二个氧化物窗口来实现的。
Using the conventional MOS planar process, miniature cantilever and doubly supported mechanical beams are fabricated from polycrystalline silicon. Poly-Si micromechanical beams having thicknesses of 230 nm to 2.3/~ m and separated by 550 nm to 3.5/~ m from the substrate are made in a wide range of lengths and widths. Two static mechanical properties are investigated: the dependences of maximum free-standing length and beam deflection on the thickness of the beam. By annealing the poly-Si prior to beam formation, both of these properties are improved. Nonuniform internal stress in the poly-Si is apparently responsible for the beam deflection.A novel method is described for making eantilever and doubly supported micromechanical beams from polycrystalline silicon (poly-Si). Only two masking steps are needed, as illustrated in Fig. 1. The first step, Fig. la, opens windows in an oxide layer grown or deposited on the silicon wafer. Next, poly-Si is deposited and plasma-etched in a second masking step, leaving the cross-section of Fig. lb. Immersing the wafer in buffered HF removes all oxide, undercutting the poly-Si layer and creating the cantilever beam, illustrated in Fig. lc. Doubly supported beams, Fig. td, are made by including a second oxide window at the opposite end of the beam.