US RE40,028 E1
Liquid crystal display device and method of manufacturing the same
Kwangjo Hwang, Kyonggi-do (Korea, Republic of); and Changwook Han, Seoul (Korea, Republic of)
Assigned to LG. Philips LCD Co., Ltd., Seoul (Korea, Republic of)
Filed on Jan. 07, 2004, as Appl. No. 10/752,486.
Application 10/752486 is a reissue of application No. 09/580590, filed on May 30, 2000, now 6,337,284, filed on Jan. 08, 2002.
Claims priority of application No. 99-19145 (KR), filed on May 27, 1999.
Int. Cl. H01L 21/302 (2006.01); H01L 21/461 (2006.01)
U.S. Cl. 438—710  [438/718; 438/719; 438/720; 438/725; 257/59; 257/247] 50 Claims
OG exemplary drawing
 
1. A method of manufacturing a liquid crystal display device, comprising:
a first photolithography process forming a gate electrode on a substrate;
a second photolithography process including:
a) depositing sequentially a gate insulating layer, a semiconductor layer, and a metal layer;
b) applying a first photoresist on the metal layer;
c) aligning a first photo mask with the substrate;
d) light exposing and developing the first photoresist to produce a first photoresist pattern;
e) etching the metal layer using a first etchant, the first etchant ashing the first photoresist pattern on a portion of the metal layer to produce a second photoresist pattern, thereby exposing the portion of the metal layer; and
f) etching the gate insulating layer, the semiconductor layer, and the portion of the metal layer using a second etchant according to the second photoresist pattern to form source and drain electrodes, an ohmic contact layer, and an active area;
a third photolithography process forming a passivation film and a contact hole; and
a fourth photolithography process forming a pixel electrode connecting with the drain electrode through the contact hole.