A source-drain electrode of a thin film transistor and its preparation method, a thin film transistor and its preparation method

Abstract

The invention discloses a source-drain electrode of a thin film transistor. The source-drain electrode is composed of a molybdenum layer and a copper layer in a sequential overlaying mode, and the copper layer is arranged on the molybdenum layer. The molybdenum layer is arranged on an active layer of the thin film transistor; the growth direction of crystal lattices of the molybdenum layer and the growth direction of crystal lattices of the copper layer are perpendicular to each other; the thickness of the molybdenum layer is 20 nm-40 nm; the thickness of the copper layer is 150 nm-250 nm. The invention further discloses a manufacturing method of the source-drain electrode, the thin film transistor comprising the source-drain electrode and a manufacturing method of the thin film transistor. The defects that in the prior art, copper electrodes are prone to being oxidized, and copper atoms diffuse toward oxide after the copper electrodes deposit on the active layer of the metal oxide are overcome, the source-drain electrode has the advantage of high conductivity, stress balance between two layers of electrodes can be achieved, the disbanding ratio of the electrodes is lowered, and the bonding strength is improved.

Description

technical field [0001] The invention relates to the field of preparation of thin film transistors, in particular to a source and drain electrode of a thin film transistor and a preparation method, the thin film transistor and a preparation method. Background technique [0002] A thin film transistor (Thin Film Transistor, TFT for short) is a semiconductor device with a wide range of uses, and is mainly used in displays to drive liquid crystal alignment changes, or to drive OLED pixels to emit light. The structure of the thin film transistor at least includes a gate, a gate insulating layer, an active layer, and source and drain electrodes. [0003] With the popularity of large-size, high-resolution, high-refresh rate displays, TFT must have excellent mobility and conductivity in order to shorten signal delay, reduce energy consumption, and improve display quality. [0004] The mobility is mainly determined by the active layer material of the TFT. Currently popular active l...

AI Technical Summary

Problems solved by technology

Silver is prone to aggregation of silver particles during deposition, which seriously affects electron transport. In addition, the cost of silver is very expensive, which limits the use of silver electrodes.

[0006] Copper is ideal in terms of resistivity, stability and cost, but copper has the following problems: 1) copper is easily oxidized, and the resistivity of copper oxide is relatively high; 2) copper electrodes are deposited on metal oxides. After the source layer is on, copper atoms will diffuse to the oxide, and acceptor-like defects will be generated in the active layer, which will degrade the electrical properties of the active layer; 3) The contact resistance between copper (including silver) and metal oxides is high, It shows that the energy level does not match; 4) The copper electrode itself has tensile stress (stress > 0), and it will warp and peel off after being deposited on the active layer

Images