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:
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 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 method of fabricating high-quality, substantially relaxed SiGe-on-insulator substrate materials which may be used as a template for strained Si is described. A silicon-on-insulator substrate with a very thin top Si layer is used as a template for compressively strained SiGe growth. Upon relaxation of the SiGe layer at a sufficient temperature, the nature of the dislocation motion is such that the strain-relieving defects move downward into the thin Si layer when the buried oxide behaves semi-viscously. The thin Si layer is consumed by oxidation of the buried oxide/thin Si interface. This can be accomplished by using internal oxidation at high temperatures. In this way the role of the original thin Si layer is to act as a sacrificial defect sink during relaxation of the SiGe alloy that can later be consumed using internal oxidation.
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:
A method of forming a high-quality relaxed SiGe alloy layer on a bulk Si-containing substrate is provided. The method of the present invention includes growing a strained SiGe alloy layer on a Si-containing substrate that has a porous Si-containing layer at or near the surface of the Si-containing substrate. The porous layer is formed by an electrolytic anodization process. The pores create free volume below the strained SiGe layer which can serve to accommodate strain relaxation during SiGe deposition or a subsequent heating step. The subsequent heating step is optional and is performed to further increase the relaxation of the SiGe alloy layer. The buried porous structure allows for a unique relaxation mechanism compared to prior art methods.
摘要:
A method of fabricating high-quality, substantially relaxed SiGe-on-insulator substrate materials which may be used as a template for strained Si is described. A silicon-on-insulator substrate with a very thin top Si layer is used as a template for compressively strained SiGe growth. Upon relaxation of the SiGe layer at a sufficient temperature, the nature of the dislocation motion is such that the strain-relieving defects move downward into the thin Si layer when the buried oxide behaves semi-viscously. The thin Si layer is consumed by oxidation of the buried oxide/thin Si interface. This can be accomplished by using internal oxidation at high temperatures. In this way the role of the original thin Si layer is to act as a sacrificial defect sink during relaxation of the SiGe alloy that can later be consumed using internal oxidation.
摘要:
Techniques for the fabrication of semiconductor devices are provided. In one aspect, a layer transfer structure is provided. The layer transfer structure comprises a carrier substrate having a porous region with a tuned porosity in combination with an implanted species defining a separation plane therein In another aspect, a method of forming a layer transfer structure is provided. In yet another aspect, a method of forming a thee dimensional integrated structure is provided.
摘要:
A strained (tensile or compressive) semiconductor-on-insulator material is provided in which a single semiconductor wafer and a separation by ion implantation of oxygen process are used. The separation by ion implantation of oxygen process, which includes oxygen ion implantation and annealing creates, a buried oxide layer within the material that is located beneath the strained semiconductor layer. In some embodiments, a graded semiconductor buffer layer is located beneath the buried oxide layer, while in other a doped semiconductor layer including Si doped with at least one of B or C is located beneath the buried oxide layer.