US Patent 11916071 Semiconductor device having epitaxy source/drain regions

A device includes first and second semiconductor fins, first, second, third and fourth fin sidewall spacers, and first and second epitaxy structures. The first and second fin sidewall spacers are respectively on opposite sides of the first semiconductor fin. The third and fourth fin sidewall spacers are respectively on opposite sides of the second semiconductor fin. The first and third fin sidewall spacers are between the first and second semiconductor fins and have smaller heights than the second and fourth fin sidewall spacers. The first and second epitaxy structures are respectively on the first and second semiconductor fins and merged together.