| CPC H01L 21/76229 (2013.01) [H10D 62/115 (2025.01); H10D 84/0151 (2025.01); H10D 84/0158 (2025.01); H10D 84/038 (2025.01); H10D 84/834 (2025.01)] | 20 Claims |
|
1. A semiconductor device comprising:
a first plurality of fins protruding from a substrate;
a base over and joined to a top surface of the substrate;
a second plurality of fins overlapping and joined to the base, wherein a difference between a first height of the first plurality of fins and a second height of the second plurality of fins is in a range from 10 nm to 60 nm, the first plurality of fins having a first width between a first sidewall of a fin of the first plurality of fins and nearest sidewall of an adjacent fin of the first plurality of fins, and the second plurality of fins having a second width between a second sidewall of a fin of the second plurality of fins and nearest sidewall of an adjacent fin of the second plurality of fins, wherein a first ratio of the second height to the second width is smaller than a second ratio of the first height to the first width;
an isolation region disposed between adjacent fins of the first plurality of fins, wherein a top surface of the isolation region is substantially at a same level as a top surface of the base;
first source/drain regions disposed in the second plurality of fins, wherein each first source/drain region in a fin of the second plurality of fins is separate from an adjacent first source/drain region in an adjacent fin of the second plurality of fins; and
second source/drain regions disposed in the first plurality of fins, wherein bottom surfaces of the second source/drain regions are below the top surface of the isolation region and below the top surface of the base.
|