Title:
HEIGHT MEASURING APPARATUS FOR WAFER
Document Type and Number:
Japanese Patent JPS59188931
Kind Code:
A
Abstract:
PURPOSE:To obtain an accurately measured value of height of a wafer by a method wherein linearly polarized lights vertical and in parallel with the incident surfaces are made to enter at the Brewster angle corresponding to the refractive index of a resist applied on the surface of the wafer, reflected lights are separated into linearly polarized lights in parallel and vertical to the reflected surfaces, lights thereof are received by light receiving elements, and height of the wafer is computed according to outputs thereof. CONSTITUTION:A laser beam 4 radiated from a laser beam source 3 is made to enter in a resist 1' applied on the surface of a wafer 1 by the Brewster angle thetaB corresponding to the refractive index of the resist thereof. Then reflected lights 5a, 6b from the wafer 1 and the resist 1' are isolated into linearly polarized lights in parallel and vertical to the reflected surfaces by a reflector 10, and the respective lights are made to enter in a double refraction type polarizer 11 through a lens 7. After then, lights 5a', 5a'' refracted at this part are received by light receiving elements 12a, 12b consisting respectively of light receiving cells 14, outputs thereof are sent to a detection signal measuring circuit 13, and operational treatment is performed to decide height of the wafer. Accordingly, height of the surface can be decided regardless of unefenness, etc. of a wiring pattern.
Inventors:
MURASHITA TATSU
FUJINAMI AKIHIRA
FUJINAMI AKIHIRA
Application Number:
JP6335883A
Publication Date:
October 26, 1984
Filing Date:
April 11, 1983
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
International Classes:
G01B11/02; H01L21/027; H01L21/66; (IPC1-7): G01B11/02; H01L21/30
Attorney, Agent or Firm:
Masaki Yamakawa