Method for manufacturing a liquid crystal display substrate

• US 5,413,958 A
• Filed: 11/16/1993
• Issued: 05/09/1995
• Est. Priority Date: 11/16/1992
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Hama, Kiichi, Hata, Jiro, Imahashi, Issei
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US08/153,376
• Time in Patent Office: 539 Days
• Field of Search: 437/173, 437/174, 437/913, 437/51, 437/907, 437/205, 148/DIG. 90, 148/DIG. 91, 148/DIG. 92, 148/DIG. 150
• US Class Current: 438/487
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: Y10S 148/006 Apparatus
• CPC Class Codes: Y10S 148/09 Laser anneal
• CPC Class Codes: Y10S 148/15 Silicon on sapphire SOS

Abstract

An amorphous silicon film is formed on a glass substrate by a CVD method, and then the island regions of the amorphous silicon film is changed to a plurality of polycrystalline silicon regions which are arranged in a line and apart with each other in a predetermined distanced by intermittently irradiating laser pulses each having the same dimensions as those of the island region onto the amorphous silicon film, using a laser beam irradiating section. Switching elements including the island regions as semiconductor regions are formed by etching and film-forming process to constitute a driving circuit section. The section is divided to gate driving circuit sections and source driving circuit sections for driving thin film transistors formed in a pixel region.

Claims

1. A method of manufacturing a liquid crystal display substrate comprising a substrate, a plurality of semiconductor elements arranged in a pixel region of the substrate, and a plurality of drive circuit sections for driving the semiconductor elements, said method comprising the steps of:

forming an amorphous semiconductor film on said substrate;

intermittently applying laser beam pulses having a cross section of predetermined dimensions, onto target surface regions of said amorphous semiconductor film, thereby changing said target surface regions into island-shaped polycrystalline regions having dimensions substantially identical to said predetermined dimensions;

forming the drive circuit sections by using said island-shaped polycrystalline regions; and

forming said semiconductor elements in said pixel region and electrically connecting said semiconductor elements to said drive circuit sections, by using parts of said amorphous semiconductor film.

2. The method according to claim 1, wherein said island-shaped polycrystalline regions are rectangular regions located outside said pixel region, arranged in a straight line and spaced apart one from another by a predetermined distance.

3. The method according to claim 1, wherein each of said island-shaped polycrystalline regions is formed by applying a plurality of laser beam pulses onto one target surface region.

4. The method according to claim 3, wherein each of said laser beam pulses applied has energy greater than the other laser beam pulse applied immediately before onto the target surface region.

5. The method according to claim 3, wherein said laser beam pulses applied onto said one target surface region have the same energy.

6. The method according to claim 5, wherein said amorphous semiconductor film has a thickness ranging from 300 Å

to 1500 Å

, said substrate is maintained at a temperature ranging from normal temperature to 550°

C., and said number of times ranges from 30 to 1000.

7. The method according to claim 6, wherein said amorphous semiconductor film has a thickness ranging from 500 Å

to 1000 Å

.

8. The method according to claim 3, wherein it is detected, upon application of every laser beam pulse, how much said one target surface has been crystallized, and application of a laser beam pulse is terminated when it is detected that said one target surface has been crystallized to a predetermined degree.

9. The method according to claim 1, wherein said amorphous semiconductor film is an amorphous silicon film.

10. A method of manufacturing a liquid crystal display substrate comprising a substrate, a plurality of semiconductor elements arranged in a pixel region of the substrate, and at least one shift register for driving the semiconductor elements, said method comprising the steps of:

forming an amorphous semiconductor film on said substrate;

applying laser beam pulses onto target surface regions of said amorphous semiconductor film, thereby changing said target surface regions into a plurality of island-shaped polycrystalline regions;

forming parts of said at least one shift register in said island-shaped polycrystalline regions, each part of said at least one shift register comprising transistors; and

forming wiring layers, thereby electrically connecting the parts of said at least one shift register to one another, and electrically connecting said at least one shift register to said semiconductor elements.