Manufacturing method of gallium nitride based heterojunction gas sensitive sensor

Abstract

The invention relates to fields of material structure design and crystal epitaxial growth, and especially relates to a manufacturing method of a gallium nitride based heterojunction gas sensitive sensor. The manufacturing method is characterized by comprising the following steps: (1) growing a low temperature gallium nitride nucleating layer on a substrate; (2) then growing a non-intentionally doped gallium nitride high resistivity layer; (3) growing an InGaN inserted layer at a temperature of 700 to 850 DEG C; (4) growing a thin low temperature gallium nitride isolation layer; (5) growing non-intentionally doped gallium nitride layer with a high mobility on the low temperature gallium nitride isolation layer; (6) growing an aluminum nitride inserted layer on the non-intentionally doped gallium nitride layer with a high mobility; (7) growing three AlGaN barrier layers with gradient contents of aluminum on the aluminum nitride inserted layer; (8) growing non-intentionally doped gallium nitride cap layer at a temperature of 1000 to 1100 DEG C; (9) depositing a schottky electrode with a gas sensing character on the non-intentionally doped gallium nitride cap layer.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, in particular to a method for manufacturing a gallium nitride-based heterojunction gas sensor. Background technique [0002] Semiconductor gas sensors are components made of metal oxide or metal semiconductor oxide materials. When interacting with gas, surface adsorption or reaction occurs, causing conductivity or volt-ampere characteristics or surface potential changes characterized by carrier movement. According to its gas sensing mechanism, non-resistive semiconductor gas sensors generally adopt Schottky structure. Taking hydrogen sensing as an example to illustrate the working principle of this type of sensor: when the Schottky diode is in contact with hydrogen, hydrogen is adsorbed on the catalyst The metal surface is decomposed into hydrogen atoms under the catalysis of the metal, and the hydrogen atoms diffuse from the metal surface to the gold / semi-interface through the lattice gap...

AI Technical Summary

Problems solved by technology

Due to this traditional fabrication, in order to obtain higher sensing sensitivity (i.e. current change rate), a higher concentration of two-dimensional electron gas is usually required, which requires a higher aluminum composition in the AlGaN barrier layer, At the same time, the confinement of the two-dimensional electron gas by the traditional structure only depends on the triangular potential well formed at the heterojunction of AlGaN and GaN, so the confinement effect on the two-dimensional electron gas is limited, so when GaN-based heterojunction When the mass junction gas sensor is working, if a larger drain voltage is applied, it will cause a certain buffer layer leakage, which will cause the current to drop and affect the measurement.

At the same time, due to the poor surface morphology of the AlGaN barrier layer with high aluminum composition, metals with gas sensing characteristics such as Pt electrodes are not easy to fabricate on its surface.

Images