Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.