Glass passivating technique process for semi-conductor device with silicon large diameter round wafer

Abstract

A glass passivation technique for large-diameter silicon wafer semiconductor devices is characterized by utilizing cutting and photoetching processes to isolate a passivating glass film layer between chips on a silicon substrate before thinning the back surface of the substrate of the large-diameter silicon wafer, or utilizing a screen mask isolating process to isolate the passivating glass film layer between the chips on the silicon substrate during glass passivation. Glass-silicon internal stress caused by difference of passivating glass-silicon thermal expansion coefficients in the glass passivation process can be effectively released or eliminated in a small range among chips, thereby effectively preventing silicon wafer warping, cracking or breaking caused by thinning the back surface of the substrate of the large-diameter silicon wafer. The technique can guarantee realization of the optimum designs of electric parameters and reliability for silicon semiconductor devices during glass passivation, and is particularly adaptable to large scale production of glass-passivated semiconductor devices with large-diameter silicon wafers.

Description

Technical field: [0001] The invention belongs to the technical field of surface passivation of semiconductor devices, and is mainly applied to the surface passivation of silicon semiconductor devices. Background technique: [0002] In the glass passivation process technology of semiconductor devices, there are mainly two types of passivation glass currently used, namely, lead-based passivation glass and zinc-based passivation glass. The electrical, chemical, and thermal properties required by semiconductor devices should be met in order to ensure the processability of the process and the electrical performance and reliability of the passivated device. [0003] The originally developed glass passivation technology is mainly used in low-frequency and high-power semiconductor devices. Although the composition of the passivation glass has been carefully designed, there is always a difference in the thermal expansion coefficient of glass and silicon during the thermoforming proce...

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Problems solved by technology

However, the above measures still have major shortcomings, mainly: even if the glass formula is improved under the premise of ensuring the glass passivation effect, it is difficult to achieve a complete match between the thermal expansion coefficient of glass and silicon and the uniformity of this match with temperature changes ; In the process of glass passivation thermoforming, it is necessary to optimize the reverse characteristics of the device and at the same time minimize the internal stress of glass-silicon. The two are not unified under the same heat treatment conditions, so it is difficult to coordinate Taking into account; intentionally leaving a thick silicon substrate when thinning the back is not conducive to heat dissipation of the device, which will increase the junction temperature of the device during operation and affect the long-term working life. For power devices, the key power indicators will be significantly reduced, while for radio frequency For the device, it will significantly increase the high-frequency loss; the above methods are still difficult to solve various drawbacks in internal stress, electrical performance or reliability

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