Methods of formation of a SiGe/Si superlattice
AssigneeApplied Materials, Inc.
InventorsJohn Tolle, Thomas Kirschenheiter, Joe Margetis, Patricia M. Liu, Zuoming Zhu, Flora Fong-Song Chang
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Abstract
A method and apparatus for forming a super-lattice structure on a substrate is described herein. The super-lattice structure includes a plurality of silicon-germanium layers and a plurality of silicon layers disposed in a stacked pattern. The methods described herein produce a super-lattice structure with transition width of less than about 1.4 nm between each of the silicon-germanium layers and an adjacent silicon layer. The methods described herein include flowing one or a combination of a silicon containing gas, a germanium containing gas, and a halogenated species.
Claims20
A method of forming a semiconductor device, comprising:
- (a) introducing a first silicon containing gas at a first flow rate and a germanium containing gas at a second flow rate into a deposition chamber to form a silicon-germanium layer on a substrate within the deposition chamber;
- (b) stopping the flow of the first silicon containing gas and the germanium containing gas into the deposition chamber after forming the silicon-germanium layer;
- (c) flowing a halogenated species into the deposition chamber;
- and
- (d) flowing a second silicon containing gas at a third flow rate greater than the first flow rate into the deposition chamber to form a silicon layer on the substrate within the deposition chamber.
A method of forming a semiconductor device, comprising:
- forming a unit cell comprising:
- introducing a silicon containing gas and a germanium containing gas into a deposition chamber to form a silicon-germanium layer on a substrate within the deposition chamber;
- stopping the flow of the germanium containing gas into the deposition chamber after forming the silicon-germanium layer;
- flowing a halogenated species into the deposition chamber;
- and
- forming a silicon layer on the substrate within the deposition chamber from the silicon containing gas, the halogenated species flowing at a first flow rate during the introducing of the silicon containing gas and the germanium containing gas, the first flow rate of the halogenated species is increased to a second flow rate prior to the forming of the silicon layer, and the first flow rate is increased to the second flow rate simultaneously to or after the stopping of the flow of the germanium containing gas;
- and
- repeating the forming the unit cell to form a stack of unit cells.
A super-lattice device structure, comprising:
- a first unit cell comprising:
- a first silicon-germanium layer;
- and
- a first silicon layer disposed on the first silicon-germanium layer, wherein a transition width between the first silicon-germanium layer and the first silicon layer is less than 1.4 nm;
- and
- a second unit cell comprising:
- a second silicon-germanium layer;
- and
- a second silicon layer disposed on the second silicon-germanium layer, wherein the transition width between the second silicon-germanium layer and the second silicon layer is less than 1.4 nm.
Dependencies are inferred from the claim text.