Epitaxial growth of doped film for source and drain regions

A method of growing a doped epitaxial material, comprising:

• providing a semiconductor substrate, wherein the semiconductor substrate has an epitaxial surface and an amorphous surface;
• performing a first cyclic deposition-deposition-etch (CDDE) process to grow a first portion of the doped epitaxial material over the epitaxial surface and not on the amorphous surface, wherein each cycle of the first CDDE process forms a first doped epitaxial material and a second doped epitaxial material, wherein a portion of the second doped epitaxial material is removed an etch process in each cycle of the CDDE process, and wherein the first portion of the doped epitaxial material has a first average dopant concentration of N-type dopants;
• and
• performing a second CDDE process to grow a second portion of the doped epitaxial material over the first portion of the doped epitaxial material, wherein a process sequence of the second CDDE process is similar to the first CDDE process;
• and wherein the second portion of the doped epitaxial material has a second average dopant concentration of N-type dopants.

A method of forming a semiconductor device on a semiconductor substrate, comprising:

• providing the substrate with a first plurality of fins and a second plurality of gate structures;
• forming spacers on each of the second plurality of gate structures;
• etching portions of the first plurality of fins not covered by the plurality of gate structures to form recesses in the first plurality of fins below exposed surfaces of isolation structures between the first plurality of fins, wherein the recesses are below surfaces of isolation structures neighboring the fins;
• and
• forming doped source and drain regions for the second plurality of gate structures by epitaxially growing the at least one silicon-containing material from the recesses, wherein a CDDE process is used for the epitaxially growing, and wherein each cycle of the CDDE process forms a first doped epitaxial material and a second doped epitaxial material, wherein a portion of the second doped epitaxial material is removed an etch process in each cycle of the CDDE process.