Semiconductor device including finFET and fin varactor

A method of forming a semiconductor device comprising:

• patterning a semiconductor substrate including a first region and a second region so as to form a plurality of semiconductor fins;
• recessing the first region with respect to a second region so as to form a first semiconductor fin in the first region having a first total height and a second semiconductor fin in the second region having a second total height that is less than the first total height;
• and
• doping a first fin portion of the first semiconductor fin to form a finFET and entirely doping the second semiconductor fin to form a fin varactor,
• wherein recessing the first region further comprises:
• depositing a masking layer atop the first and second regions so as to cover the first semiconductor fin and the second semiconductor fin, and selectively patterning the masking layer to expose the first region while maintaining coverage of the second region;
• depositing a conformal spacer layer that covers first sidewalls and an upper surface of the first semiconductor fin and second sidewalls and an upper masking surface of the masking layer;
• performing a first etching process selective to the conformal spacer layer so as to expose the semiconductor substrate of the first region;
• and
• performing a second etching process selective to the semiconductor substrate so as to recess the first region with respect to the second region.

A method of forming a semiconductor device comprising:

• patterning a semiconductor substrate including a first region and a second region so as to form a plurality of semiconductor fins;
• recessing the first region with respect to a second region so as to form a first semiconductor fin in the first region having a first total height and a second semiconductor fin in the second region having a second total height that is less than the first total height;
• reducing a thickness of a first portion of the first semiconductor fin so as to adjust a first resistance of the first semiconductor fin with respect to a second resistance of the second semiconductor fin;
• and
• doping the first portion of the first semiconductor fin to form a finFET and entirely doping the second semiconductor fin to form a fin varactor.