Semiconductor devices and method of forming the same

A method of forming a semiconductor device, comprising:

• providing a semiconductor structure comprising a first region, a second region and a sacrificial gate structure between the first region and the second region, wherein the sacrificial gate structure comprises at least one metal layer and wraps around a plurality of sacrificial semiconductor nanosheets;
• performing a first wet etching process by using a first etching solution, to clean a surface of the sacrificial gate structure, wherein the first etching solution contains a base and a first oxidant;
• performing at least one cycle, each cycle comprising:
• performing a second wet etching process by using a second etching solution, to remove the at least one metal layer of the sacrificial gate structure, wherein the second etching solution contains an acid and a second oxidant;
• and
• performing a cleaning process;
• performing an etching process to remove the sacrificial semiconductor nanosheets, to form an opening between the first region and the second region.

A semiconductor device, comprising:

• a first region, comprising a plurality of first semiconductor nanosheets and a first gate structure wrapping around each of the first semiconductor nanosheets;
• a second region, comprising a plurality of second semiconductor nanosheets and a second gate structure wrapping around each of the second semiconductor nanosheets;
• and
• a separation region between the first region and the second region, comprising:
• a dielectric pattern, electrically isolating the first gate structure and the second gate structure;
• and
• a spacer on a sidewall of the dielectric pattern, wherein the spacer comprises a sidewall in direct contact with the dielectric pattern and a top surface, and a turning point is formed between the top surface and the sidewall of the spacer.