Methods for preserving strained semiconductor substrate layers during CMOS processing
    42.
    发明授权
    Methods for preserving strained semiconductor substrate layers during CMOS processing 有权
    在CMOS处理期间保留应变半导体衬底层的方法

    公开(公告)号:US07416909B2

    公开(公告)日:2008-08-26

    申请号:US11702825

    申请日:2007-02-06

    IPC分类号: H01L21/00 H01L21/338

    摘要: Oxidation methods, which avoid consuming undesirably large amounts of surface material in Si/SiGe heterostructure-based wafers, replace various intermediate CMOS thermal oxidation steps. First, by using oxide deposition methods, arbitrarily thick oxides may be formed with little or no consumption of surface silicon. These oxides, such as screening oxide and pad oxide, are formed by deposition onto, rather than reaction with and consumption of the surface layer. Alternatively, oxide deposition is preceded by a thermal oxidation step of short duration, e.g., rapid thermal oxidation. Here, the short thermal oxidation consumes little surface Si, and the Si/oxide interface is of high quality. The oxide may then be thickened to a desired final thickness by deposition. Furthermore, the thin thermal oxide may act as a barrier layer to prevent contamination associated with subsequent oxide deposition.

    摘要翻译: 避免在Si / SiGe异质结构基晶片中消耗不希望的大量表面材料的氧化方法代替了各种中间CMOS热氧化步骤。 首先,通过使用氧化物沉积方法,可以形成少量或不消耗表面硅的任意厚的氧化物。 这些氧化物,例如筛选氧化物和氧化垫,通过沉积到表面层上而不是与表面层反应并消耗而形成。 或者,氧化物沉积之前是短时间的热氧化步骤,例如快速热氧化。 这里,短的热氧化消耗很少的表面Si,并且Si /氧化物界面是高质量的。 然后可以通过沉积将氧化物增稠至所需的最终厚度。 此外,薄的热氧化物可以用作阻挡层,以防止与随后的氧化物沉积相关的污染。