Method and apparatus for regulating exhaust pressure in evacuation system of semiconductor process chamber

An apparatus for regulating exhaust pressure in a semiconductor process chamber, said apparatus comprising:

• a vacuum pump having an exhaust side and an intake side coupled with said semiconductor process chamber for generating a first pressure in said semiconductor process chamber;
• a throttle valve positioned between said semiconductor process chamber and said vacuum pump to create an exhaust pressure in-between said semiconductor process chamber and said vacuum pump;
• a first pressure sensor for monitoring said first pressure to generate a first signal in said semiconductor process chamber;
• a second pressure sensor for monitoring said exhaust pressure in said intake side;
• and
• a controller responsive to said first signal to regulate said exhaust pressure in said intake side to a set point, wherein said first pressure is higher than said set point of said exhaust pressure, and a smooth downstream exhaust can be maintained and by-products generated can be exhausted from the semiconductor process chamber through the apparatus for regulating exhaust pressure.

A method for regulating exhaust pressure in an evacuation system of a semiconductor process chamber, said method comprising:

• generating a first pressure in said semiconductor process chamber and an exhaust pressure in-between said semiconductor process chamber and said evacuation system with said evacuation system;
• monitoring said first pressure to generate a first signal;
• determining a set point for said exhaust pressure responsive to said first signal;
• and
• regulating said exhaust pressure to said set point to secure and maintain said first pressure higher than said exhaust pressure, so that a smooth downstream exhaust can be maintained and by-products generated can be exhausted from the semiconductor process chamber through the evacuation system.