Epitaxy Regions with Large Landing Areas for Contact Plugs

A device comprising:

• a semiconductor substrate;
• isolation regions extending into the semiconductor substrate;
• a protruding semiconductor fin protruding higher than top surfaces of the isolation regions;
• a gate stack on a top surface and sidewalls of the protruding semiconductor fin;
• and
• a source/drain region on a side of the gate stack, the source/drain region comprising:
• a first semiconductor layer comprising a first vertical edge and a second vertical edge parallel to each other;
• and
• a second semiconductor layer on the first semiconductor layer, wherein the second semiconductor layer extends both laterally and vertically from the first semiconductor layer.

A device comprising:

• a plurality of isolation regions comprising a first portion and a second portion;
• a semiconductor strip between and contacting the first portion and the second portion;
• a source/drain region overlapping the semiconductor strip, the source/drain region comprising:
• a first semiconductor layer comprising:
• a first vertical edge and a second vertical edge on (110) planes of the first semiconductor layer;
• and
• a first slanted top surface and a second slanted top surface joining with each other to form a triangle, wherein the first slanted top surface and the second slanted top surface are connected to the first vertical edge and the second vertical edge, respectively;
• and
• a second semiconductor layer on the first semiconductor layer.