Back channel etched oxide semiconductor tft substrate and method of making the same

Abstract

The invention provides a back channel etching type oxide semiconductor TFT substrate and a manufacturing method thereof. In the manufacturing method of the back channel etching type oxide semiconductor TFT substrate of the present invention, the active layer is set as a double-layer structure, the first oxide semiconductor layer located in the lower layer is prepared according to normal deposition process parameters, and has a normal density, and the first oxide semiconductor layer located in the upper layer is prepared according to normal deposition process parameters and has a normal density. The dioxide semiconductor layer is prepared by changing the deposition process parameters and has a higher density; the first oxide semiconductor layer has a lower density and has a higher mobility, and the second oxide semiconductor layer has a higher density, The thin film has few defects and strong etching resistance, which can reduce the damage to the channel region of the active layer during the etching process of the drain and source electrodes, saves the mask of the etching barrier layer at the same time, and has low production cost.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a back channel etching type oxide semiconductor TFT substrate and a manufacturing method thereof. Background technique [0002] Liquid crystal display (Liquid Crystal Display, LCD) has many advantages such as thin body, power saving, no radiation, etc., and has been widely used, such as: mobile phone, personal digital assistant (PDA), digital camera, computer screen or notebook computer screen etc. [0003] Organic light-emitting diode (Organic Light-Emitting Diode, OLED) display, also known as organic electroluminescent display, is a new type of flat panel display device, due to its simple preparation process, low cost, low power consumption, high luminance, Wide range of working temperature, light and thin size, fast response speed, easy to realize color display and large-screen display, easy to realize matching with integrated circuit driver, easy to realize flexible display...

AI Technical Summary

Problems solved by technology

However, the preparation process of IGZO TFT with ESL structure is relatively complicated, and it needs to go through six yellow light processes, which is not conducive to reducing costs. Therefore, the industry generally pursues the development of IGZO TFT with back channel etching (BCE) structure with fewer yellow light processes.

[0012] Since the IGZO TFT of the BCE structure is not provided with an etching barrier layer to block the back channel, the channel region of the IGZO active layer is easily damaged during the etching process of the source and drain electrodes, and due to the number of film defects in the IGZO active layer More, so IGZO TFT is sensitive to the environment, light, water vapor (H 2 O), oxygen (O 2 ), hydrogen (H 2 ) and organics (Organics) are likely to affect the performance of the TFT, resulting in lower reliability of the TFT device and a shorter service life of the panel

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