Tft photodetector integrated on display panel

Abstract

A method of fabricating a thin-film transistor (TFT) photodetector includes forming diffusion layers on a glass substrate or a transparent flexible substrate, wherein the diffusion layers include a P-type diffusion layer of P-type polycrystalline or amorphous silicon, for use as an active layer and P+-type diffusion layers of amorphous or polycrystalline silicon at both sides of the P-type diffusion layer, forming an insulating oxide layer on the formed diffusion layers, forming an N-type diffusion layer of polycrystalline or amorphous silicon on the insulating oxide film, forming a gate to be used as a light receiving part by photo-patterning the N-type diffusion layer, etching the generated insulating oxide layer except for only a necessary part in a photoresist (PR) patterning process, removing a remaining area of the P+-type diffusion layer except for areas to be used as a source and a drain by etching, and generating electrodes by depositing a metal in etched parts of the insulating oxide film in the source and the drain.

What is claimed is: 
     
         1 . A method of fabricating a thin-film transistor (TFT) photodetector, the method comprising:
 forming diffusion layers on a glass substrate or a transparent flexible substrate, wherein the diffusion layers include a P-type diffusion layer of P-type polycrystalline or amorphous silicon, for use as an active layer and P+-type diffusion layers of amorphous or polycrystalline silicon at both sides of the P-type diffusion layer;   forming an insulating oxide layer on the formed diffusion layers;   forming an N-type diffusion layer of polycrystalline or amorphous silicon on the insulating oxide film;   forming a gate to be used as a light receiving part by photo-patterning the N-type diffusion layer;   etching the generated insulating oxide layer except for only a necessary part in a photoresist (PR) patterning process;   removing a remaining area of the P+-type diffusion layer except for areas to be used as a source and a drain by etching; and   generating electrodes by depositing a metal in etched parts of the insulating oxide film in the source and the drain.   
     
     
         2 . The method according to  claim 1 , wherein the insulating oxide film is formed by sputtering or plasma enhanced chemical vapor deposition (PECVD). 
     
     
         3 . The method according to  claim 1 , wherein the N-type diffusion layer is formed by depositing amorphous silicon and then crystallizing the deposited amorphous silicon by thermal treatment, or directly depositing polycrystalline silicon on the transparent substrate.