公开(公告)号：US06521041B2

公开(公告)日：2003-02-18

申请号：US09289514

申请日：1999-04-09

申请人： Kenneth C. Wu ,  Eugene A. Fitzgerald ,  Jeffrey T. Borenstein

发明人： Kenneth C. Wu ,  Eugene A. Fitzgerald ,  Jeffrey T. Borenstein

IPC分类号： C30B2502

CPC分类号： H01L21/02505 ,  H01L21/02381 ,  H01L21/0245 ,  H01L21/0251 ,  H01L21/02532 ,  H01L21/2007 ,  H01L21/30608 ,  H01L21/76256 ,  Y10S117/915

摘要： A SiGe monocrystalline etch-stop material system on a monocrystalline silicon substrate. The etch-stop material system can vary in exact composition, but is a doped or undoped Si1−xGex alloy with x generally between 0.2 and 0.5. Across its thickness, the etch-stop material itself is uniform in composition. The etch stop is used for micromachining by aqueous anisotropic etchants of silicon such as potassium hydroxide, sodium hydroxide, lithium hydroxide, ethylenediamine/pyrocatechol/pyrazine (EDP), TMAH, and hydrazine. For example, a cantilever can be made of this etch-stop material system, then released from its substrate and surrounding material, i.e., “micromachined”, by exposure to one of these etchants. These solutions generally etch any silicon containing less than 7×1019 cm−3 of boron or undoped Si1−xGex alloys with x less than approximately 18. Alloying silicon with moderate concentrations of germanium leads to excellent etch selectivities, i.e., differences in etch rate versus pure undoped silicon. This is attributed to the change in energy band structure by the addition of germanium. Furthermore, the nondegenerate doping in the Si1−xGex alloy should not affect the etch-stop behavior. The etch-stop of the invention includes the use of a graded-composition buffer between the silicon substrate and the SiGe etch-stop material. Nominally, the buffer has a linearly-changing composition with respect to thickness, from pure silicon at the substrate/buffer interface to a composition of germanium, and dopant if also present, at the buffer/etch-stop interface which can still be etched at an appreciable rate. Here, there is a strategic jump in germanium and concentration from the buffer side of the interface to the etch-stop material, such that the etch-stop layer is considerably more resistant to the etchant.

摘要翻译： 单晶硅衬底上的SiGe单晶蚀刻停止材料体系。 蚀刻停止材料系统可以精确的组成变化，但是掺杂或未掺杂的Si1-xGex合金，其x通常在0.2和0.5之间。 在其厚度上，蚀刻停止材料本身在组成上是均匀的。 蚀刻终止剂用于由诸如氢氧化钾，氢氧化钠，氢氧化锂，乙二胺/邻苯二酚/吡嗪（EDP），TMAH和肼的水的各向异性蚀刻剂的微加工。 例如，悬臂可以由该蚀刻停止材料体系制成，然后通过暴露于这些蚀刻剂之一从其衬底和周围的材料即“微加工”释放。 这些溶液通常蚀刻含有小于7×10 19 cm -3的小于7×10 19 cm -3的x或x x小于约18的未掺杂的Si1-xGex合金的硅。使用适度浓度的锗合金化硅导致优异的蚀刻选择性，即蚀刻速率与纯未掺杂的差异 硅。 这归因于通过添加锗的能带结构的变化。 此外，Si1-xGex合金中的非退化掺杂不应影响蚀刻停止性能。 本发明的蚀刻停止包括在硅衬底和SiGe蚀刻停止材料之间使用渐变组成缓冲液。 名义上，缓冲液具有相对于厚度的线性变化的组成，从衬底/缓冲液界面处的纯硅到锗的组成，以及如果还存在，则在缓冲/蚀刻 - 停止界面处的掺杂剂，其仍然可以在 一个明显的利率。 在这里，从界面的缓冲侧到蚀刻停止材料的锗和浓度存在着战略上的跳跃，使得蚀刻停止层相对于蚀刻剂更具有抵抗力。

公开(公告)号：US06689211B1

公开(公告)日：2004-02-10

申请号：US09599260

申请日：2000-06-22

申请人： Kenneth C. Wu ,  Eugene A. Fitzgerald ,  Jeffrey T. Borenstein ,  Gianna Taraschi

发明人： Kenneth C. Wu ,  Eugene A. Fitzgerald ,  Jeffrey T. Borenstein ,  Gianna Taraschi

IPC分类号： C30B2522

CPC分类号： H01L21/30608 ,  H01L21/76256 ,  Y10S117/915

摘要： A SiGe monocrystalline etch-stop material system on a monocrystalline silicon substrate. The etch-stop material system can vary in exact composition, but is a doped or undoped Si1−xGex alloy with x generally between 0.2 and 0.5. Across its thickness, the etch-stop material itself is uniform in composition. The etch stop is used for micromachining by aqueous anisotropic etchants of silicon such as potassium hydroxide, sodium hydroxide, lithium hydroxide, ethylenediamine/pyrocatechol/pyrazine (EDP), TMAH, and hydrazine. These solutions generally etch any silicon containing less than 7×1019 cm−3 of boron or undoped Si1−xGex alloys with x less than approximately 18. Alloying silicon with moderate concentrations of germanium leads to excellent etch selectivities, i.e., differences in etch rate versus pure undoped silicon. This is attributed to the change in energy band structure by the addition of germanium. Furthermore, the nondegenerate doping in the Si1−xGex alloy should not affect the etch-stop behavior. The etch-stop of the invention includes the use of a graded-composition buffer between the silicon substrate and the SiGe etch-stop material. Nominally, the buffer has a linearly-changing composition with respect to thickness, from pure silicon at the substrate/buffer interface to a composition of germanium, and dopant if also present, at the buffer/etch-stop interface which can still be etched at an appreciable rate. Here, there is a strategic jump in germanium and concentration from the buffer side of the interface to the etch-stop material, such that the etch-stop layer is considerably more resistant to the etchant. This process and layer structure allows for an entire range of new materials for microelectronics. The etch-stop capabilities introduce new novel processes and structures such as relaxed SiGe alloys on Si, SiO2, and SiO2/Si. Such materials are useful for future strained Si MOSFET devices and circuits.

公开(公告)号：US07227176B2

公开(公告)日：2007-06-05

申请号：US10603852

申请日：2003-06-25

申请人： Kenneth C. Wu ,  Eugene A. Fitzgerald ,  Gianni Taraschi ,  Jeffrey T. Borenstein

发明人： Kenneth C. Wu ,  Eugene A. Fitzgerald ,  Gianni Taraschi ,  Jeffrey T. Borenstein

IPC分类号： H01L29/06

CPC分类号： H01L21/02505 ,  H01L21/02381 ,  H01L21/0245 ,  H01L21/0251 ,  H01L21/02532 ,  H01L21/2007 ,  H01L21/30608 ,  H01L21/76256

摘要： A semiconductor structure including a uniform etch-stop layer. The uniform etch stop layer has a relative etch rate which is less than approximately the relative etch rate of Si doped with 7×1019 boron atoms/cm3. A method for forming a semiconductor structure includes forming a uniform etch-stop layer providing a handle wafer, and bonding the uniform etch-stop layer to the handle wafer. The uniform etch-stop layer has a relative etch rate which is less than approximately the relative etch rate of Si doped with 7×1019 boron atoms/cm3.

摘要翻译： 包括均匀蚀刻停止层的半导体结构。 均匀的蚀刻停止层的相对蚀刻速率小于约7×10 19硼原子/ cm 3的Si的相对蚀刻速率。 一种用于形成半导体结构的方法包括形成均匀的蚀刻停止层，提供处理晶片，并将均匀的蚀刻停止层结合到处理晶片。 均匀的蚀刻停止层的相对蚀刻速率小于约7×10 19个硼原子/ cm 3掺杂的Si的相对蚀刻速率。