Patent ID: 6893882

Claim:
A method of process control comprising: providing a plurality of tools and a plurality of products to be run on said tools; identifying tool effects on a parameter for each tool and product effects on parameter for each product; calculating a desired recipe for each product on each tool based on said tool effects and said product effects; thereafter running said plurality of products on said plurality of tools; updating said desired recipe after each run of each tool; and calculating tool aging after each run of each said tool based on said desired recipe used wherein said product effects are denoted by P(i) for i=1, . . . , m and wherein said tool effects are denoted by T(j) for j=1, . . . , n and wherein said desired recipe for each recipe(i,j) is calculated by using the following equation 1: recipe( i,j )= P ( i )× T ( j )+ C ( i,j ) wherein C(i,j) is an error term.