Uniform epitaxial growth over crystalline template

A method of filling a trench in a semiconductor structure, comprising:

• performing a pre-clean process on exposed surfaces of a semiconductor structure, the semiconductor structure comprising a first semiconductor region, a second semiconductor region separated from the first semiconductor region by a trench, and a dielectric layer over at least a portion of the first semiconductor region and the second semiconductor region;
• performing a first deposition process to form an amorphous silicon-containing layer on the exposed surfaces of the semiconductor structure;
• performing a recrystallization anneal process to recrystallize portions of the amorphous silicon-containing layer in direct contact with the first semiconductor region and the second semiconductor region to form a silicon-containing crystalline layer in direct contact with the first semiconductor region and the second semiconductor region within the trench;
• performing an etch process to remove remaining portions of the amorphous silicon-containing layer in direct contact with the dielectric layer;
• and
• performing a second deposition process, to epitaxially form a source/drain region over the silicon-containing crystalline layer within the trench.