METHOD FOR MAKING A TFT ACTIVE MATRIX FOR A PROJECTION SYSTEM SCREEN

摘要

A method for making a liquid crystal display active matrix with four masking levels where the control transistors are of the top-gate type. The resulting liquid crystal display is particularly suitable for use in projection display systems. The method comprises, inter alia, the steps of depositing and etching a first opaque level (1) on a transparent insulating plate (2); depositing an insulating transparent film (3); depositing and etching a transparent conductor (7); selectively depositing an ohmic contact then depositing an intrinsic semiconductor material and a gate insulator (8), and performing a first etching of the resulting assembly; depositing and etching an opaque conductive level (9); and performing a second etching of the semiconductor (7) and gate insulator (8) level using the mask of the opaque conductive level (9).