Manufacturing method of back-channel-etching oxide thin-film transistor

Abstract

The invention discloses a manufacturing method of a back-channel-etching oxide thin-film transistor. The method sequentially comprises the following steps: (a) manufacturing a first thin-film layer on a substrate by a direct-current sputtering method and carrying out patterning; (b) manufacturing a second thin-film layer by the direct-current sputtering method and carrying out patterning; (c) manufacturing a third thin-film layer by the direct-current sputtering method and carrying out patterning as a source-drain electrode; and (d) putting the whole semi-finished product into electrochemical oxidation equipment for electrochemical oxidation, completely oxidizing a second patterned thin-film layer to form a second oxide layer, partially oxidizing a first patterned thin-film layer, and forming an oxide layer corresponding to a first thin-film layer material on the upper surface of the first patterned thin-film layer as a first oxide layer, wherein the unoxidized part of the first thin-film layer is taken as the residual first thin-film layer; the second oxide layer is taken as an active layer; the first oxide layer is taken as a gate insulation layer; and the residual first thin-film layer is taken as a gate. According to the manufacturing method, manufacturing is carried out at room temperature; radio-frequency sputtering is not needed; the manufacturing technique is simple; the production efficiency is high; and defects are few.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a preparation method of an oxide thin film transistor. Background technique [0002] In recent years, the new flat panel display (FPD) industry has developed rapidly. Consumers' high demand for large-size, high-resolution flat-panel displays has stimulated the entire industry to continuously improve display technologies. The thin-film transistor (TFT) backplane technology, which is the core technology of the FPD industry, is also undergoing profound changes. Oxide TFTs not only feature high mobility and transparency to visible light, but also have excellent large-area uniformity. Therefore, the oxide TFT technology has attracted the attention of the industry since its birth. [0003] However, due to the low conductivity of the oxide semiconductor active layer, it is usually prepared by radio frequency sputtering. Compared with DC sputtering, RF sputtering has disadvant...

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Problems solved by technology

Compared with DC sputtering, RF sputtering has disadvantages such as slow speed, constant adjustment and matching, poor process repeatability, uneven composition of multi-element films, and large RF radiation.

In addition, due to the high process temperature of the insulating layer and semiconductor active layer, it is difficult to be compatible with flexible substrates

[0004] On the other hand, when wet etching is used to etch the source and drain electrodes on the active layer, because the active layer is sensitive to most acidic etching solutions, it is easy to be corroded during the etching process, so for Back channel etched metal oxide thin film transistors, it is difficult to directly etch the source and drain electrodes directly on the active layer

In the prior art, the active layer is generally protected by adding an etching barrier layer, but an additional photolithography process is required to form the etching barrier layer, which increases the process cost of the oxide thin film transistor

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