Patent ID: 11966170
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 7:
8. A method comprising:
receiving a wafer;
calculating a topographical variation based on a surface topography of the wafer; and
determining to perform a single-zone alignment compensation when the topographical variation is less than a predetermined value, and, alternatively, to perform a multi-zone alignment compensation when the topographical variation is greater than the predetermined value;
performing a wafer alignment according to the single-zone alignment compensation or the multi-zone alignment compensation; and
performing an exposure after the wafer alignment,, wherein the multi-zone alignment compensation further comprises:
defining a plurality of zones over the wafer, wherein the plurality of zones includes a first zone, a second zone and an Nth zone, and each of the first zone, the second zone and the Nth zone includes a plurality of fields;
performing a first multi-zone alignment compensation by a controller to obtain a first compensation value for the fields in the first zone, wherein the first multi-zone alignment compensation includes an equation (1), and the equation (1) is:

dX1=α1*Z1+β1*Z2+γ1*Z3+ . . . ω1*Zn  (1)

wherein dX1 indicates the first compensation value for the fields in the first zone, Z1 to Zn indicate the first zone to the Nth zone of the plurality of zones, α1 indicates a weighting for the fields in the first zone in the first multi-zone alignment compensation, β1 indicates a weighting for the fields in the second zone in the first multi-zone alignment compensation, γ1 indicates a weighting for the fields in the third zone in the first multi-zone alignment compensation, and ω1 indicates a weighting for the fields in the Nth zone in the first multi-zone alignment compensation; and
performing a second multi-zone alignment compensation by the controller to obtain a second compensation value for the fields in the second zone, wherein the second multi-zone alignment compensation includes an equation (2), and the equation (2) is:

dX2=α2*Z1+β2*Z2+γ2*Z3+ . . . ω2*Zn  (2), wherein dX2 indicates the second compensation value for the fields in the second zone, α2 indicates a weighting for the fields in the first zone in the second multi-zone alignment compensation, β2 indicates a weighting for the fields in the second zone in the second multi-zone alignment compensation, γ2 indicates a weighting for the fields in the third zone in the second multi-zone alignment compensation, and ω2 indicates a weighting for the fields in the Nth zone in the second multi-zone alignment compensation.