Preparation method of gas sensor and gas sensor

Abstract

The invention provides a preparation method of a gas sensor and the gas sensor. The method comprises the following steps of providing a wafer which is provided with a silicon substrate and a buffer layer on the surface; growing an N-type semiconductor layer on the surface of the buffer layer; etching the N-type semiconductor layer, the buffer layer and part of the silicon substrate to form a trench; forming electrodes on two sides of the surface of the N-type semiconductor layer; forming a conductive layer on the surfaces of the N-type semiconductor layer, the buffer layer and the silicon substrate; removing the redundant conductive layer to form a conductive layer covering the wafer at the groove; and growing a nanowire at the conductive layer, and forming a suspended nanowire in the trench. The gas sensor based on in-situ bridging growth of the ZnO nanowires is low in contact resistance and working voltage, annealing treatment is not needed, and large-scale preparation of the high-performance on-chip gas sensor is facilitated.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a method for preparing a gas sensor and the gas sensor. Background technique [0002] In the prior art, semiconductor metal oxide nanowires are widely used to prepare gas sensors due to their performance advantages such as high specific surface area, high crystal quality and quasi-one-dimensional carrier transport. Zinc oxide (ZnO) is an excellent N-type multifunctional semiconductor material, and ZnO nanowires have been widely studied for high-performance gas sensors. Traditional nanowire sensors are usually prepared by transfer. Nanowires are grown on a certain substrate or in a solution, then dispersed in a volatile solvent, transferred to a functional substrate by spin-coating or wetting, and then transferred to a functional substrate by light. Electrode structures are prepared by microelectronic processes such as engraving, sputtering, and lift-off. Although this method is wi...

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Problems solved by technology

However, at present, most ZnO nanowires grown by in-situ bridging growth are directly grown on metal electrodes. Although this method can realize wafer-level device fabrication, it introduces a Schottky barrier between ZnO and electrodes, which increases the If the annealing treatment is performed after growing ZnO nanowires, it will deteriorate the crystal quality of the nanowires and reduce the performance of the device.

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