ScAlN/GaN double-barrier resonant tunneling diode and manufacturing method thereof

Abstract

The invention discloses an ScAlN/GaN double-barrier resonant tunneling diode and a manufacturing method thereof. The ScAlN/GaN double-barrier resonant tunneling diode mainly solves the problems that an existing gallium nitride resonant tunneling diode is low in peak current, small in peak-valley current ratio and asymmetric in differential negative resistance effect. The ScAlN/GaN double-barrier resonant tunneling diode comprises a substrate, a GaN epitaxial layer, an n+GaN emitter ohmic contact layer, a GaN isolation layer, a first barrier layer, a GaN quantum well layer, a second barrier layer, an isolation layer, a collector ohmic contact layer and a collector electrode from bottom to top, wherein the two barrier layers both adopt ScAlN which has an Sc component range of 15% to 20% and a thickness of 1-3 nm and is identical in the Sc component and thickness; the isolation layer is made of InN with a thickness of 2-4 nm; and the collector ohmic contact layer adopts n+InN. The ScAlN/GaN double-barrier resonant tunneling diode is high in peak current, large in peak-valley current ratio, capable of achieving forward and reverse symmetrical differential negative resistance effect, high in working frequency and output power and applicable to a high-frequency terahertz radiation source and a high-speed digital circuit.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a ScAlN / GaN double potential barrier resonant tunneling diode, which can be used for high-frequency terahertz radiation sources and high-speed digital circuits. Background technique [0002] Resonant tunneling diode is a vertical structure quantum effect device, which has the characteristics of differential negative resistance, low junction capacitance, short carrier transport time, unipolar transport, etc., and its working frequency can reach terahertz frequency band. Oscillators prepared based on resonant tunneling diode devices have the advantages of high frequency and low power consumption, and are one of the ways to realize terahertz radiation sources. They are widely used in security detection, spectral imaging, high-speed wireless communication and circuit design. With the advancement of material growth technology and device fabrication process, I...

AI Technical Summary

Problems solved by technology

[0005] One is that there is a large lattice mismatch in the AlGaN / GaN / AlGaN double-barrier quantum well. The active region of the device has a high density of dislocations, and the interface of the quantum well is rough and uneven. These material defects act as scattering centers and leakage channels, and ultimately reduce the device The peak current increases the valley current to degrade the differential negative resistance effect;

[0006] The second is that there is a strong piezoelectric polarization and spontaneous polarization electric field in the AlGaN / GaN / AlGaN double barrier quantum well, which modulates the band structure of the quantum well and affects the transport of the device under forward and reverse bias. characteristics, producing an asymmetrical differential negative resistance effect;

[0007] The third is that there is a wide depletion region on the collector side of the GaN resonant tunneling diode, which reduces the probability of electron tunneling under reverse bias and weakens the differential negative resistance characteristics under reverse bias;

[0008] Fourth, the ohmic contact resistance of the collector is high, and the series resistance of the device is high, which increases the peak voltage of the resonance tunneling differential negative resistance effect and the power consumption of the device;

[0009] Fifth, the distribution of dislocations in the active area of ​​the device is uneven, resulting in unstable device performance and low reliability. The device performance decreases with the increase in size, and the performance consistency of the same size device is poor.

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