Patent ID: 9716145
Date: 2017-07-25
CPC Classifications: B82Y,H01L

Claim:
1. A method for manufacturing a semiconductor device, comprising: epitaxially growing a plurality of silicon layers and a plurality of compressively strained silicon germanium (SiGe) layers on a substrate in a stacked configuration, wherein the plurality of silicon layers and the plurality of compressively strained SiGe layers are alternately stacked on each other starting with a silicon layer on a bottom of the stacked configuration, wherein a compressive strain in each of the plurality of compressively strained SiGe layers is maintained by the plurality of silicon layers contacting the plurality of compressively strained SiGe layers, and wherein the plurality of compressively strained SiGe layers form channel regions of the semiconductor device; patterning the stacked configuration to a first width; selectively removing a portion of each of the plurality of silicon layers in the stacked configuration to reduce each of the plurality of silicon layers to a second width less than the first width; performing a condensation process after the selective removal of the portion of each of the plurality of silicon layers from the stacked configuration, wherein the plurality of silicon layers reduced by the selective removal are fully oxidized during the condensation process, and the condensation process results in an oxide layer on the substrate and on remaining portions of the stacked configuration, the oxide layer including fully oxidized silicon portions formed in place of each silicon layer, wherein a compressive strain in each of the plurality of compressively strained SiGe layers is maintained by the fully oxidized silicon portions contacting the plurality of compressively strained SiGe layers; removing the oxide layer from side portions of the plurality of compressively strained SiGe layers; and removing part of the oxide layer from top and bottom portions of the plurality of compressively strained SiGe layers, wherein remaining portions of the oxide layer on the top and bottom portions of the plurality of compressively strained SiGe layers are in the stacked configuration and have a smaller width than a width of the plurality of compressively strained SiGe layers, the remaining portions of the oxide layer not being removed from the stacked configuration, thereby maintaining the compressive strain in each of the plurality of compressively strained SiGe layers.