Fabrication method of back channel etching type oxide semiconductor TFT substrate

Abstract

The invention provides a method for manufacturing a back channel etching type oxide semiconductor TFT substrate. Firstly, a first passivation layer is deposited on the source electrode, the drain electrode and the active layer, and then the plasma containing oxygen is used to treat the The surface of the first passivation layer is treated so that a trace amount of oxygen element penetrates into the shallow surface layer of the channel region of the active layer through the first passivation layer, and supplements the oxygen element to the shallow surface layer of the channel region, Ensure the balance of oxygen elements in the shallow surface layer, and in the plasma treatment process, the first passivation layer acts as a barrier layer for the source and drain electrodes, so that only trace amounts of oxygen elements can reach the source and drain electrodes, It is not enough to oxidize the source and drain to ensure the stability of the TFT.

Description

technical field [0001] The present invention relates to the field of display technology, in particular to a method for manufacturing a back-channel etched oxide semiconductor TFT substrate. Background technique [0002] 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 (OLED) display, also known as organic electroluminescent display, is an emerging flat panel display device, due to its simple preparation process, low cost, low power consumption, high luminous brightness, It has a wide range of working temperature adaptation, light and thin volume, fast response speed, easy to achieve color display and large-screen display, easy to achieve matching with integrated circuit drivers, easy to achieve flexible display and other advantages, so it ...

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.

[0011] The realization of the IGZO TFT with BCE structure is to remove the etch stop layer (Etch Stop Layer) while using metal copper to make the source and drain, so as to achieve the purpose of reducing one yellowing process. However, the existing copper etching solution will inevitably Causes a certain degree of damage to the IGZO active layer, changes the surface characteristics of the IGZO active layer, and deteriorates the stability of the TFT substrate

At present, the commonly used copper etching solution is hydrogen peroxide (H 2 o 2 ) system, the etching damage to the IGZO active layer is small, especially the fluorine (F) element-free copper etching solution, but it is verified by experiments that the F-free copper etching solution still has damage to the IGZO active layer, especially It is the damage to the oxygen (O) element balance in the shallow surface layer of the back channel, and it is easy to affect the leakage current (I off ) and job stability

Images