摘要:
A method is disclosed for forming a strained Si layer on SiGe, where the SiGe layer has improved thermal conductivity. A first layer of Si or Ge is deposited on a substrate in a first depositing step; a second layer of the other element is deposited on the first layer in a second depositing step; and the first and second depositing steps are repeated so as to form a combined SiGe layer having a plurality of Si layers and a plurality of Ge layers. The respective thicknesses of the Si layers and Ge layers are in accordance with a desired composition ratio of the combined SiGe layer (so that a 1:1 ratio typically is realized with Si and Ge layers each about 10 Å thick). The combined SiGe layer is characterized as a digital alloy of Si and Ge having a thermal conductivity greater than that of a random alloy of Si and Ge. This method may further include the step of depositing a Si layer on the combined SiGe layer; the combined SiGe layer is characterized as a relaxed SiGe layer, and the Si layer is a strained Si layer. For still greater thermal conductivity in the SiGe layer, the first layer and second layer may be deposited so that each layer consists essentially of a single isotope.
摘要:
A substrate material including a Si-containing substrate and an insulating region that is resistant to Ge diffusion present atop the Si-containing substrate. The substrate material further includes a substantially relaxed SiGe alloy layer present atop the insulating region, wherein the substantially relaxed SiGe alloy layer has a planar defect density from about 5000 defects/cm−2 or less. The substrate material may be employed in a heterostructure, in which a strained Si layer is present atop the substantially relaxed SiGe alloy layer of the substrate material.
摘要翻译:包含含Si衬底和耐Ge扩散的绝缘区的衬底材料存在于含Si衬底顶部。 衬底材料还包括存在于绝缘区域顶部的基本弛豫的SiGe合金层,其中基本上松弛的SiGe合金层具有约5000个缺陷/ cm -2或更小的平面缺陷密度。 衬底材料可以用于异质结构,其中应变Si层存在于衬底材料的基本上松弛的SiGe合金层顶上。
摘要:
A heterostructure is provided which includes a substantially relaxed SiGe layer present atop an insulating region that is located on a substrate. The substantially relaxed SiGe layer has a thickness of from about 2000 nm or less, a measured lattice relaxation of from about 50 to about 80% and a defect density of less than about 108 defects/cm2. A strained epitaxial Si layer is located atop the substantially relaxed SiGe layer and at least one alternating stack including a bottom relaxed SiGe layer and an top strained Si layer located on the strained epitaxial Si layer.
摘要翻译:提供了异质结构,其包括位于衬底上的绝缘区域上的基本上松弛的SiGe层。 基本上松弛的SiGe层具有约2000nm或更小的厚度,约50至约80%的测量晶格弛豫和小于约108缺陷/ cm 2的缺陷密度。 应变外延Si层位于基本上松弛的SiGe层之上,并且至少一个交替堆叠包括位于应变外延Si层上的底部松弛SiGe层和顶部应变Si层。
摘要:
A method of forming a low-defect, substantially relaxed SiGe-on-insulator substrate material is provided. The method includes first forming a Ge-containing layer on a surface of a first single crystal Si layer which is present atop a barrier layer that is resistant to Ge diffusion. A heating step is then performed at a temperature that approaches the melting point of the final SiGe alloy and retards the formation of stacking fault defects while retaining Ge. The heating step permits interdiffusion of Ge throughout the first single crystal Si layer and the Ge-containing layer thereby forming a substantially relaxed, single crystal SiGe layer atop the barrier layer. Moreover, because the heating step is carried out at a temperature that approaches the melting point of the final SiGe alloy, defects that persist in the single crystal SiGe layer as a result of relaxation are efficiently annihilated therefrom. In one embodiment, the heating step includes an oxidation process that is performed at a temperature from about 1230° to about 1320° C. for a time period of less than about 2 hours. This embodiment provides SGOI substrate that have minimal surface pitting and reduced crosshatching.
摘要:
A method of forming a silicon germanium on insulator (SGOI) structure. A SiGe layer is deposited on an SOI wafer. Thermal mixing of the SiGe and Si layers is performed to form a thick SGOI with high relaxation and low stacking fault defect density. The SiGe layer is then thinned to a desired final thickness. The Ge concentration, the amount of relaxation, and stacking fault defect density are unchanged by the thinning process. A thin SGOI film is thus obtained with high relaxation and low stacking fault defect density. A layer of Si is then deposited on the thin SGOI wafer. The method of thinning includes low temperature (550° C.-700° C.) HIPOX or steam oxidation, in-situ HCl etching in an epitaxy chamber, or CMP. A rough SiGe surface resulting from HIPOX or steam oxidation thinning is smoothed with a touch-up CMP, in-situ hydrogen bake and SiGe buffer layer during strained Si deposition, or heating the wafer in a hydrogen environment with a mixture of gases HCl, DCS and GeH4.
摘要:
A method for fabricating substantially relaxed SiGe alloy layers with a reduced planar defect density is disclosed The method of the present invention includes forming a strained Ge-containing layer on a surface of a Si-containing substrate; implanting ions at or below the Ge-containing layer/Si-containing substrate interface and heating to form a substantially relaxed SiGe alloy layer that has a reduced planar defect density. A substantially relaxed SiGe-on-insulator substrate material having a SiGe layer with a reduced planar defect density as well as heterostructures containing the same are also provided.
摘要:
The present invention provides a method of fabricating a SiGe-on-insulator substrate in which lattice engineering is employed to decouple the interdependence between SiGe thickness, Ge fraction and strain relaxation. The method includes providing a SiGe-on-insulator substrate material comprising a SiGe alloy layer having a selected in-plane lattice parameter, a selected thickness parameter and a selected Ge content parameter, wherein the selected in-plane lattice parameter has a constant value and one or both of the other parameters, i.e., thickness or Ge content, have adjustable values; and adjusting one or both of the other parameters to final selected values, while maintaining the selected in-plane lattice parameter. The adjusting is achieved utilizing either a thinning process or a thermal dilution process depending on which parameters are fixed and which are adjustable.
摘要:
A method of forming a low-defect, substantially relaxed SiGe-on-insulator substrate material is provided. The method includes first forming a Ge-containing layer on a surface of a first single crystal Si layer which is present atop a barrier layer that is resistant to Ge diffusion. A heating step is then performed at a temperature that approaches the melting point of the final SiGe alloy and retards the formation of stacking fault defects while retaining Ge. The heating step permits interdiffusion of Ge throughout the first single crystal Si layer and the Ge-containing layer thereby forming a substantially relaxed, single crystal SiGe layer atop the barrier layer. Moreover, because the heating step is carried out at a temperature that approaches the melting point of the final SiGe alloy, defects that persist in the single crystal SiGe layer as a result of relaxation are efficiently annihilated therefrom. In one embodiment, the heating step includes an oxidation process that is performed at a temperature from about 1230° to about 1320° C. for a time period of less than about 2 hours. This embodiment provides SGOI substrate that have minimal surface pitting and reduced crosshatching.
摘要:
High-quality, metastable SiGe alloys are formed on SOI substrates having an SOI layer of about 500 Å or less, the SiGe layers can remain substantially fully strained compared to identical SiGe layers formed on thicker SOI substrates and subsequently annealed and/or oxidized at high temperatures. The present invention thus provides a method of ‘frustrating’ metastable strained SiGe layers by growing them on thin, clean and high-quality SOI substrates.
摘要:
A high-quality, substantially relaxed SiGe-on-insulator substrate material which may be used as a template for strained Si is described. The substantially relaxed SiGe-on-insulator substrate includes a Si-containing substrate, an insulating region that is resistant to Ge diffusion present atop the Si-containing substrate, and a substantially relaxed SiGe layer present atop the insulating region. The insulating region includes an upper region that is comprised of a thermal oxide and the substantially relaxed SiGe layer has a thickness of about 2000 nm or less.