SILICON GERMANIUM-ON-INSULATOR FORMATION BY THERMAL MIXING
A layer of amorphous silicon is formed on a germanium-on-insulator substrate, or a layer of germanium is formed on a silicon-on-insulator substrate. An anneal is then performed which causes thermal mixing of silicon and germanium atoms within one of the aforementioned structures and subsequent formation of a silicon germanium-on-insulator material.
1 . A method of forming a silicon germanium-on-insulator (SGOI) material, said method comprising:
providing a structure comprising, from bottom to top, a silicon-on-insulator substrate and a germanium layer; and
converting said structure into a silicon germanium-on-insulator material by annealing, wherein during said annealing silicon atoms from a silicon layer of said silicon-on-insulator substrate intermix with germanium atoms in said germanium layer to form a silicon germanium layer.
2 . The method of claim 1 , wherein said silicon layer of said silicon-on-insulator substrate is single crystalline.
3 . The method of claim 1 , wherein said germanium layer is continuously present on a topmost surface of said silicon layer of said silicon-on-insulator substrate.
4 . The method of claim 1 , wherein said germanium layer has an epitaxial relationship with said silicon layer of said silicon-on-insulator substrate.
5 . The method of claim 1 , wherein said germanium layer is hydrogenated.
6 . The method of claim 1 , wherein said germanium layer is completely consumed by said annealing.
7 . The method of claim 1 , wherein said germanium layer is partially consumed by said annealing.
8 . The method of claim 7 , further comprising removing a remaining portion of said germanium layer.
9 . The method of claim 1 , further comprising forming a dielectric material on a surface of said germanium layer prior to said converting.
10 . The method of claim 1 , further comprising forming an amorphous region at an interface between said germanium layer and said silicon layer of said silicon-on-insulator substrate prior to said converting.
11 . The method of claim 10 , wherein said forming said amorphous region comprises ion implanting an amorphizing ion into said structure prior to said annealing.
12 . The method of claim 11 , wherein said amorphizing ion comprises Si or Ge.
13 . The method of claim 11 , wherein said ion implanting is performed at or below room temperature.
14 . The method of claim 10 , wherein said amorphous region is a continuously present between said germanium layer and said silicon layer of said silicon-on-insulator substrate.
15 . The method of claim 10 , wherein said annealing crystallizes said amorphous region.
16 . The method of claim 1 , wherein said annealing is a thermal anneal performed in hydrogen.
17 . The method of claim 1 , wherein said silicon germanium layer has a germanium content from greater than 50 atomic percent germanium to 90 atomic percent germanium.