Polysilicon Devices and a Method for Fabrication Thereof
Thin film transistors (TFTs) fabricated on polycrystalline silicon (polysilicon) have gained much attention in flat panel displays such as active matrix liquid crystal displays (LCDs) and in static random access memory (SRAM) units. In comparison with thick film devices TFT devices made with a thin film have the advantages of lower grain boundary trap density, higher mobility, and higher on-state current. It is desirable to make the thin film transistor as thin as possible in order to provide a high supply current in the on-state.
The invention relates to novel designs of semiconductor devices and to a method for their fabrication. A novel thin film transistor device, comprising source and drain regions formed of doped polysilicon and interconnected by a polysilicon channel region are invented. Such a transistor having advantages of both conventional thin and thick film devices including high drive current and low leakage current in the off state. The fabrication method for this transistor may also be adapted to manufacture other novel semiconductor devices including semiconductor capacitance devices, EEPROM devices, and conductivity modulated TFTs.
1. Low leakage current and high on-state current
2. No impact ionization and high trapped charge density problem
3. Electric field at the channel or drain junction are reduced
4. The grain boundary trapped charges are reduced
5. Higher mobility
- Display technology
- SRAM memory applications
- Semiconductor devices including semiconductor capacitance devices, EEPROM devices, and conductivity modulated TFTs
Patent Number: US5982004A
Application Number: US1997879886A
Inventor: Sin, Johnny Kin On | Kottarath Parambil, Anish Kumar
Priority Date: 20 Jun 1997
Priority Number: US5982004A
Application Date: 20 Jun 1997
Publication Date: 9 Nov 1999
IPC Current: G02F0001136 | G02F00011368 | H01L0021225 | H01L0021336 | H01L002712 | H01L002978 | H01L0029786 | H01L0029788
US Class: 257347 | 257316 | 257348 | 257350 | 257E21412 | 257E21422 | 257E27111 | 257E29275 | 257E29302
Assignee Applicant: The Hong Kong University of Science & Technology
Title: Polysilicon devices and a method for fabrication thereof
Usefulness: Polysilicon devices and a method for fabrication thereof
Summary: USE For active matrix LCD, EEPROM, semiconductor capacitor, static RAM.
Novelty: Structure of polysilicon thin film transistor for active matrix LCD, capacitor, EEPROM includes polysilicon doped channel area whose thickness is lesser than that of source and drain areas
電子
半導體
20 Jun 1997
US 5982004
TTC.PA.057
香港
