| Popis: |
The need for process control in the semiconductor industry has been established and the benefits have been demonstrated. In the past, process control applications in the semiconductor manufacturing have relied on univariable control schemes. In the case of poly gate etch control methods have manipulated trim time or O 2 flow to maintain a target poly gate FI CD target as the input DI CD varies . This study focuses on the im pact of process control on secondary output goals and compares the e ffect of univariable control with that of multivariable control. There are two important conclusions for semiconductor manufacturers: (i) univariable control schemes sacrifice secondary control goals when trying to achieve the prim ary control goal and (ii) manufacturer s must adopt multi-input multi-output control schemes to actively control both secondary process goals and primary control goals. Keywords: Poly gate etch, process control, multivariable, univariable, targets, control goals, gate width, microloading, uniformity, chamber matching. |
