Relaxed silicon germanium substrate with low defect density
    7.
    发明授权
    Relaxed silicon germanium substrate with low defect density 有权
    具有低缺陷密度的松弛硅锗衬底

    公开(公告)号:US06878610B1

    公开(公告)日:2005-04-12

    申请号:US10228545

    申请日:2002-08-27

    摘要: A method of forming a strained silicon layer on a relaxed, low defect density semiconductor alloy layer such as SiGe, has been developed. In a first embodiment of this invention the relaxed, low density SiGe layer is epitaxially grown on an silicon layer which in turn is located on an underlying SiGe layer. During the epitaxial growth of the overlying SiGe layer defects are formed in the underlying silicon layer resulting in the desired, relaxation, and decreased defect density for the SiGe layer. A second embodiment features an anneal procedure performed during growth of the relaxed SiGe layer, resulting in additional relaxation and decreased defect density, while a third embodiment features an anneal procedure performed to the underlying silicon layer prior to epitaxial growth of the relaxed SiGe layer, again allowing optimized relaxation and defect density to be realized for the SiGe layer. The ability to obtain a strained silicon layer on a relaxed, low defect density SiGe layer, allows devices with enhanced carrier mobility to be formed in the surface of the strained silicon layer, with decreased risk of leakage due the presence of the underlying, relaxed, low defect density SiGe layer.

    摘要翻译: 已经开发了在松弛的低缺陷密度半导体合金层如SiGe上形成应变硅层的方法。 在本发明的第一实施例中,松散的低密度SiGe层在硅层上外延生长,硅层又位于下面的SiGe层上。 在覆盖SiGe层的外延生长期间,在下层硅层中形成缺陷,导致SiGe层所需的,松弛的和降低的缺陷密度。 第二个实施例的特征在于在松弛的SiGe层的生长期间执行的退火程序,导致附加的松弛和降低的缺陷密度,而第三实施例的特征在于在弛豫的SiGe层的外延生长之前对下面的硅层进行退火处理 允许为SiGe层实现优化的弛豫和缺陷密度。 在松弛的低缺陷密度SiGe层上获得应变硅层的能力允许在应变硅层的表面形成具有增强的载流子迁移率的器件,由于存在下面的,放松的, 低缺陷密度SiGe层。