TFT PHOTODETECTOR INTEGRATED ON DISPLAY PANEL
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.
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.