Patent ID: 6049216
Filing Date: 2000-04-11
Classification: G01R

Abstract:
A method for prober automatic alignment for aligning a prober having a prober alignment pattern to a wafer having a wafer alignment pattern, comprising the steps of:defining a first coordinate system having a center O.sub.1, and orthogonal X.sub.1 and Y.sub.1 axes on said wafer alignment pattern, said wafer alignment pattern including a circular region centered at O.sub.1 ;defining a second coordinate system having a center O.sub.2, and orthogonal X.sub.2 and Y.sub.2 axes on said prober alignment pattern, said prober alignment pattern including a first virtual circle centered at O.sub.2 and said Y.sub.2 axis and Y.sub.1 axis forming a prober angle;performing a pre-alignment of said prober alignment pattern to said wafer alignment pattern for positioning said center O.sub.2 within said circular region in a quadrant of said first coordinate system, said first virtual circle having a first arc portion being positioned outside said circular region and the mid-point of said first arc portion and said center O.sub.2 forming a first arc axis;acquiring a first set of measurement data for determining a first distance between said centers O.sub.1 and O.sub.2, and a first angle between said first arc axis and said Y.sub.2 axis;moving said prober alignment pattern in a direction parallel to said X.sub.1 axis or said Y.sub.1 axis by an offset distance and maintaining said center O.sub.2 within said circular region in said quadrant, said prober angle between said Y.sub.2 axis and said Y.sub.1 axis being kept constant, said first virtual circle having a second arc portion being positioned outside said circular region and the mid-point of said second arc portion and said center O.sub.2 forming a second arc axis;acquiring a second set of measurement data for determining a second distance between said centers O.sub.1 and O.sub.2, and a second angle between said second arc axis and said Y.sub.2 axis;and determining said prober angle between said Y.sub.1 axis and said Y.sub.2 axis by said first and second distances, and said first and second angles.