Patent ID: 9536990
Date: 2017-01-03
CPC Classifications: H01L

Claim:
1. A method of forming a FinFET device comprised of a replacement fin made of a material having a replacement fin coefficient of thermal expansion (replacement fin CTE) and a target final fin height for said replacement fin, the method comprising: forming a patterned fin etch mask above a semiconductor substrate, said patterned fin etch mask having a thickness that is equal to or greater than said target final fin height for said replacement fin; performing an etching process through said patterned fin etch mask to form a plurality of trenches in said semiconductor substrate so as to define a substrate fin; with said patterned fin etch mask in position, forming a layer of insulating material in said trenches; recessing said layer of insulating material so as to expose said patterned fin etch mask above a recessed upper surface of said layer of insulating material; forming a layer of CTE-matching material around said exposed patterned fin etch mask and above said recessed upper surface of said layer of insulating material, said layer of CTE-matching material having a CTE that is within ±20% of said replacement fin CTE; removing said patterned fin etch mask so as to thereby define a replacement fin cavity in at least said layer of CTE-matching material and expose a surface of said substrate fin; forming said replacement fin on said substrate fin and in said replacement fin cavity; removing said layer of CTE-matching material; and forming a gate structure around at least a portion of said replacement fin.