Patent Number: 6,295,120

Title: Position detection technique applied to proximity exposure

Abstract: The exposure surface of a wafer to be exposed is formed with a wafer mark having edges for scattering incident light. The edge of the wafer mark has a curved portion whose image vertically projected upon a plane in parallel to the exposure surface has a curved shape. The surface of an exposure mask is formed with a mask mark having edges for scattering incident light. The edge of the exposure mask has a curved portion whose image vertically projected upon a plane in parallel to the surface of the exposure mask has a curved shape. The wafer and exposure mask are juxtaposed with and spaced apart by a gap from the exposure surface of the wafer. Illumination light is applied to the curved portions of the edges of the wafer and mask marks. Light scattered from the wafer and mask marks is observed along a direction oblique to the exposure surface to thereby detect a relative position of the wafer and exposure mask.

Inventors: Miyatake; Tsutomu (Kiyose, JP)

Assignee: Sumitomo Heavy Industries, Ltd.

International Classification: G03F 9/00 (20060101); G03B 027/42 (); G03B 027/54 (); G03B 027/32 (); G01N 021/86 (); G01B 011/00 ()

Expiration Date: 09/25/2018