Process for producing thin-film transistor

• US 4,624,737 A
• Filed: 06/10/1985
• Issued: 11/25/1986
• Est. Priority Date: 08/21/1984
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Seiko Instruments & Electronics Ltd. (Seiko Group Corp.)
• Inventors: Shimbo, Masafumi
• Primary Examiner(s): Powell, William A.
• Application Number:
  US06/743,092
• Time in Patent Office: 533 Days
• Field of Search: 156/643, 156/646, 156/652, 156/653, 156/655, 156/656, 156/657, 156/659.1, 156/661.1, 156/662, 156/667, 156/668, 204/192 E, 204/192 EC, 427/38, 427/39, 427/88, 427/89, 427/90, 427/93, 427/94, 427/95, 430/313, 430/317, 430/318, 29/571, 29/576 R, 29/578, 29/591, 357/4, 357/23.1, 357/23.7, 357/65, 357/71
• US Class Current: 438/158
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/78669 with inverted-type structure, e.g. with bottom gate

Abstract

A gate insulating film, a high-resistivity semiconductor film, a low-resistivity semiconductor film and if necessary a conducting film are successively deposited in lamination without exposing them to any oxidizing atmosphere including atmospheric air, and then the source and drain electrodes are selectively formed.

Claims

1. A process for producing a thin-film transistor comprising a first step for forming a gate electrode on an insulating substrate, a second step for continuously depositing on said gate electrode and substrate a gate insulating film, a high-resistivity semiconductor film and a conducting film containing at least a low-resistivity semiconductor film without exposing them to an oxidizing atmosphere, a third step in which said high-resistivity semiconductor film and said conducting film are selectively etched so that they are partly left as an island region on said gate electrode, a fourth step for selectively forming a source electrode and a drain electrode both contacting a part of the surface of said island region and spaced apart from each other, a fifth step for selectively removing said conducting film exposed on said island region with said source and drain electrodes serving as at least a part of the mask, a sixth step for depositing a surface passivation film, and a seventh step for selectively removing said surface passivation film and exposing a part of each of said source electrode, drain electrode and gate electrode.

2. A process for producing a thin-film transistor according to claim 1, wherein in said second step said conducting film is composed of at least two layers consisting of a low-resistivity semiconductor film and thereon a refractory metal film or transparent conducting film, and both of said films are continuously deposited without being exposed to the oxidizing atmosphere.

3. A process for producing a thin-film transistor according to claim 1 , wherein in said sixth step a light-shielding film is formed at a part of said surface passivation film.

4. A process for producing a thin-film transistor according to claim 2 , wherein in said sixth step a light-shielding film is formed at a part of said surface passivation film.