Method for forming a crystalline protective polysilicon layer

A method for forming a semiconductor device, comprising:

• depositing a first dielectric layer on a substrate having at least one conductive element formed therein;
• depositing a first polysilicon layer above the first dielectric layer;
• patterning the first dielectric layer and the first polysilicon layer to form a gate structure of a Complementary Metal Oxide Semiconductor (CMOS) device;
• depositing a second dielectric layer over the patterned first dielectric layer and the first polysilicon layer;
• depositing a second polysilicon layer over the second dielectric layer, wherein the second polysilicon layer is deposited at a first temperature in a range of 600 degrees Celsius to 700 degrees Celsius;
• patterning the second dielectric layer and the second polysilicon layer;
• and
• depositing an epitaxial layer over the patterned second dielectric layer and the second polysilicon layer, wherein the epitaxial layer is treated at a second temperature in a hydrogen environment, wherein the second temperature is higher than the first temperature.

A method for forming a semiconductor device, comprising:

• providing a substrate having at least one conductive element formed therein;
• depositing a first dielectric layer on the substrate;
• depositing a first polysilicon layer above the first dielectric layer;
• patterning the first dielectric layer and the first polysilicon layer to form a gate structure of a Complementary Metal Oxide Semiconductor (CMOS) device;
• depositing a second dielectric layer over the patterned first dielectric layer and the first polysilicon layer;
• depositing a second polysilicon layer over the second dielectric layer, wherein the second polysilicon layer is deposited at a first temperature in a range of 600 degrees Celsius to 700 degrees Celsius;
• patterning the second dielectric layer and the second polysilicon layer;
• and
• depositing an epitaxial layer over the patterned second dielectric layer and the second polysilicon layer, wherein the epitaxial layer is treated at a second temperature in a hydrogen environment, wherein the second temperature is different from the first temperature.