Patent ID: 11972942
Assignee: TEXAS INSTRUMENTS INCORPORATED
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. A method of forming an integrated circuit, the method comprising:
forming a gate oxide using wet thermal oxidation by:
positioning a semiconductor wafer in a single wafer chamber;
heating the single wafer chamber to a first temperature;
while at the first temperature, exposing portions of the semiconductor wafer to hydrogen at a first hydrogen flow rate and oxygen at a first oxygen flow rate with a first nitrogen flow rate of zero to form the gate oxide;
then and while still at the first temperature:
reducing the first hydrogen flow rate to a second hydrogen flow rate;
reducing the first oxygen flow rate to a second oxygen flow rate; and
increasing the first nitrogen flow rate of zero to a second nitrogen flow rate greater than zero;

then and while still at the first temperature:
reducing the second hydrogen flow rate to a third hydrogen flow rate;
reducing the second oxygen flow rate to a third oxygen flow rate; and
increasing the second nitrogen flow rate to a third nitrogen flow rate; and

then applying a fourth hydrogen flow rate of zero, a fourth oxygen flow rate of zero and a fourth nitrogen flow rate greater than the third nitrogen flow rate during a temperature ramp down process reducing the first temperature to a second temperature.