Method for manufacturing nitride gradient energy gap resonance tunneling ohmic contact

Abstract

The invention discloses a method for manufacturing nitride gradient energy gap resonance tunneling ohmic contact. According to the method, an AlGaN / GaN heterostructure 2, an AlGaN gradient energy gap depletion layer 3 and a heavy doping GaN cap layer 4 are sequentially grown on a substrate 1 so as to manufacture the ohmic contact; the heavy doping GaN cap layer 4 can reduce the contact barrier of a metal-semiconductor; the gradient energy gap depletion layer 3 forms a middle trap to reduce the resistance of the ohmic contact through the resonance tunneling. According to the invention, by the design of the middle trap of the a gradient energy gap, the metal-semiconductor contact barrier generated in the high-temperature alloy process is separated from the heterojunction barrier, and energy bands of double-barrier and single-trap heterostructures are optimally designed respectively, so that the tunneling current is obviously increased, and the ohmic contact is reduced. Meanwhile, with the design of the heavy doping GaN cap layer, the high-temperature alloy process is omitted; the surface appearance, the device performance and the reliability of the contact are improved.

Description

technical field [0001] The invention relates to a method for manufacturing a nitride semiconductor device, in particular to a method for making an ohmic contact on a nitride heterojunction. Specifically, the AlGaN gradient transition layer and the heavily doped GaN cap layer are grown on the nitride heterostructure by the energy band tailoring method to reduce the surface barrier height and thin the surface barrier, and increase the metal-semiconductor contact. barrier tunneling current. And using the energy band tailoring method, the thickness, energy band gradient and doping concentration of the AlGaN energy band transition layer are optimally designed, and an intermediate well is formed in the transition layer energy band. Cut the energy band of the intermediate well, so that the quantum confinement state in the intermediate well and the two-dimensional electronic state in the heterojunction channel well produce resonant tunneling, so that the electrons tunneling into the ...

AI Technical Summary

Problems solved by technology

However, reducing the barrier height and thinning the barrier will deplete the two-dimensional electrons in the heterojunction channel well, and raise the well site and the barrier of the well edge of the channel well, preventing the tunneling of low-energy electrons in the metal to the channel well, thereby increasing the resistance of the ohmic contact

Therefore, although various chemical and physical methods have been exhausted to study the alloying process between metals and semiconductors, a solution to the best of both worlds has not been found to solve this problem.

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