Metal-insensitive epitaxy formation

A semiconductor device structure, comprising:

• a semiconductor substrate of a first semiconductor material and having first recesses;
• a first gate stack formed on the semiconductor substrate and being adjacent the first recesses;
• a passivation material layer of a second semiconductor material and formed in the first recesses wherein the passivation material layer includes fluorine;
• and
• first source and drain (S/D) features of a third semiconductor material and formed in the first recesses and being separated from the semiconductor substrate by the passivation material layer, wherein the second semiconductor material is different than the third semiconductor material, and wherein a top surface of the first S/D features extends beyond a top surface of a channel region.

A semiconductor device structure, comprising:

• a semiconductor substrate of a first semiconductor material and having first recesses and second recesses;
• a passivation material layer of a second semiconductor material and formed in the first and second recesses;
• and
• first source and drain (S/D) features of a third semiconductor material formed in the first recesses and second S/D features of the third semiconductor material formed in the second recesses, wherein the semiconductor substrate is separated from the first and second S/D features by the passivation material layer, wherein the second semiconductor material is different than the third semiconductor material, and wherein the first S/D features have a first conductivity type and the second S/D features have a second conductivity type different than the first conductivity type.