Manufacturing method for ohmic contact with low specific contact resistance and low roughness

Abstract

The invention discloses a manufacturing method for ohmic contact with low specific contact resistance and low roughness. The manufacturing method is characterized in that hardly compatible Mo metal is introduced to an ohmic contact metal seed to form a TiAlNiMoAu combination, thus the surface roughness and the specific contact resistance after alloying are reduced under the same alloying condition. In the manufacturing method, the low diffusivity of the Mo is utilized, and a binary alloy phase is matched, thus low contact resistance is realized, the roughness of the ohmic contact after alloying is also reduced, the overlay accuracy of a photolithographic process is improved, the number of process steps is reduced, the stability of the ohmic contact is improved, and a firm foundation is established for device process practicability.

Description

technical field [0001] The invention relates to a method for designing and manufacturing semiconductor microelectronics, in particular to a method for manufacturing an ohmic contact with low specific contact resistance and low roughness. Background technique [0002] The formation of ohmic contacts on n-type or unintentionally doped GaN and AlGaN materials is a complex process involving a variety of solid-state reactions. Using the relevant knowledge of physics, metallurgy and chemistry, the design includes multilayer The metallization system of metal may produce alloying or solid phase regrowth after heating the metallization system, thus forming an ohmic contact of "metal-GaN layer (AlGaN layer)-semiconductor". [0003] The formation of alloy ohmic contacts on GaN or AlGaN needs to meet some basic design requirements. The first is the barrier layer. The principle of selecting a metal for this layer is to form a low-resistance, low work function, thin and thermally stable ...

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Problems solved by technology

[0005] There are some reports about the TiAlMoAu system in foreign countries. The report also mentions the good effect of Mo on improving the surface morphology, but the problem of Mo adhesion is ignored. However, we have found through experiments that the thickness of Mo and the evaporation The conditions are not well controlled, and the Mo / Au two-layer metal skin is often warped or even peeled off.

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