Self-aligned double-layer channel metallic oxide thin film transistor and manufacturing method thereof

Abstract

The invention provides a self-aligned double-layer channel metallic oxide thin film transistor and a manufacturing method of the self-aligned double-layer channel metallic oxide thin film transistor. The manufacturing method comprises the following steps that a thick high-resistivity metallic oxide semiconductor layer and a thin low-resistivity metallic oxide layer deposit on a substrate, so that double layers of channels are formed; photoetching and etching are carried out on the double layers of channels, so that an active area graph is formed; a gate medium layer and a gate electrode are formed on the double layers of channels; a covering layer with H deposits on the whole substrate, then heat processing is carried out so that H can diffuse to metallic oxide outside the channel area not covered by the gate electrode and the gate medium, and a heavily doped low-resistivity source drain area is formed; a contact hole and a contact electrode are prepared. The self-aligned double-layer channel metallic oxide thin film transistor and the manufacturing method of the self-aligned double-layer channel metallic oxide thin film transistor adopt self-aligned double-layer channel top gate structure, can lower source drain resistance, lower the influence of ambient light on elements, lower off-state current, and improve on-state current and migration rate of the elements.

Description

technical field [0001] The invention relates to a thin film transistor and a preparation method thereof, in particular to a self-aligned top gate structure double-layer channel metal oxide thin film transistor and a preparation method thereof. Background technique [0002] Thin-film transistors (TFTs: thin-film transistors), as a kind of MOS device, have always been the core device of flat panel display technology. Thin film transistors are mainly used in the switch control of the pixel circuit of the flat panel display panel, the driving of the pixel circuit and the peripheral driving circuit of the display panel. In addition, thin film transistors are also widely used in sensors, memories, processors and other fields. Thin film transistors can be divided into many types according to the different materials of the active layer, including traditional silicon-based thin film transistors, metal oxide thin film transistors (Oxide TFTs) and organic thin film transistors (Organi...

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Problems solved by technology

[0005] Compared with the bottom gate structure device, the top gate structure is easy to achieve self-alignment, but the source and drain region resistance of the self-aligned top gate structure device has a great influence on the device performance. In the large-area panel production line, the low-resistance source-drain compatible with it The formation process is extremely important; moreover, top-gate structure devices are greatly affected by ambient light, and the off-state current of the device will increase under ambient light irradiation, affecting device reliability and power consumption

[0006] Although metal oxide thin film transistors have higher carrier mobility than hydrogenated amorphous silicon thin film transistors, the mobility of single-layer channel devices is only in the range of a few square centimeters per volt second to tens of square centimeters per volt second. level, can not meet the requirements of data circuit drive

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