Negative resistance type GaN pressure sensor and preparation method thereof

Abstract

The invention discloses a negative resistance type GaN pressure sensor and a preparation method thereof. The preparation method comprises the following steps: 1) sequentially growing a GaN buffer layer and an n-type GaN layer on a Si substrate; 2) growing a double-barrier AlGaN / GaN / AlGaN quantum well on the n-type GaN layer; 3) growing the n-type GaN layer on the double-barrier AlGaN / GaN / AlGaN quantum well; 4) selectively etching the epitaxial layer material to form an etch table top and a step; 5) depositing a passivation layer on the table top and the step; 6) etching the passivation layer to form an electrode hole and depositing a metal electrode; and 7) selectively etching the Si substrate to form an etching groove. Firstly, the resonant tunneling effect is utilized to regulate carriertransport process and negative resistance effect in the quantum well; and secondly, the piezoelectric polarization effect of the AlGaN / GaN heterojunction is utilized and the polarized electric fieldis changed by the external pressure so that the energy level in the quantum well is changed, the tunneling efficiency of carriers in the quantum well is controlled and the output current decreases rapidly, i.e. the negative resistance effect occurs under the external pressure so as to show the extremely high response sensitivity.

Description

technical field [0001] The invention relates to the field of pressure sensors, in particular to a negative resistance GaN pressure sensor and a preparation method thereof. Background technique [0002] Pressure sensor is currently the most commonly used sensor in the field of industrial applications. It is widely used in various industrial control environments, involving railway transportation, aerospace, military industry, water conservancy and hydropower, intelligent buildings, electric power, machine tools, ships and many other industries. [0003] Traditional semiconductor pressure sensors realize the output of electrical signals by changing the carrier concentration, mobility or capacitance under pressure, thereby realizing pressure sensing. However, in these methods, due to the small piezoelectric variation coefficient of concentration, mobility, and capacitance, the minimum applied pressure is limited, and there are nonlinear and hysteresis effects of pressure, result...

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Problems solved by technology

However, in these methods, due to the small piezoelectric variation coefficient of concentration, mobility and capacitance, the minimum applied pressure is limited, and there are nonlinear and hysteresis effects of pressure, resulting in slow pressure response and distortion.

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