A Back-end Process for Improving the Reliability of Compound Semiconductor Devices

Abstract

The invention discloses a back segment technology for improving the reliability performance of a compound semiconductor device. After a wafer finishes a front side manufacture procedure and steps including back hole, back metal layer and barrier layer manufacture and the like, the surface of the barrier layer is infiltrated by isopropyl alcohol, then, photoresist is coated and is subjected to general exposure, exposure time is controlled until photoresist out of the back hole is completely exposed and at least parts of photoresist in the back hole are not completely exposed, and development iscarried out to remove the completely exposed photoresist. After the exposed barrier layer is removed by etching, residual photoresist in the back hole is removed, and therefore, the barrier layer inthe back hole is left. By use of a method for infiltrating the barrier layer by IPA (isopropyl alcohol), the photoresist can be evenly coated in the hole, a photomask plate is not required, exposure adhesive thickness is controlled by the general exposure time, and the barrier layer guarantees to be only positioned in the back hole after etching. Compared with a traditional technological structure, the technology disclosed by the invention reduces device ground resistance, meanwhile, sintering porosity is reduced, and the reliable performance of the device is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor technology, in particular to a backstage technology for improving the reliability performance of compound semiconductor devices. Background technique [0002] Wide bandgap compound semiconductor materials, such as GaN's unique polarization effect and high electron saturation velocity, make GaN HEMT devices one of the most promising microwave power devices. [0003] In order to reduce the parasitic source inductance and improve the heat dissipation performance of the device in the manufacture of RF power devices, the processes of substrate thinning, source back hole and electroplating back gold will be adopted. Due to its good thermal conductivity during packaging, gold-tin is generally used for chip mounting. During the working process of the device in the existing process, tin solder will permeate from the back hole to the front of the device, which will cause reliability problems of the d...

AI Technical Summary

Problems solved by technology

One of the disadvantages of this process is that an additional mask is required, which increases both cost and process complexity

In addition, due to the requirements of backside lithography alignment and the limitation of the precision of the existing lithography process, the metal barrier layer formed by this method not only exists in the back hole, but also leaves a metal barrier layer outside the back hole. On the one hand, it will increase the Grounding resistance, on the other hand, the porosity at the edge of the hole will be relatively large during sintering

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