Method of monitoring planarization process of medium

Abstract

The invention discloses a method of monitoring the planarization process of a medium, comprising the steps: A. making a specific monitoring pattern in the process of making a heterojunction bipolar transistor (HBT); B. applying a photoresist to a substrate which has the monitoring pattern and is treated by the planarization of the medium by spin coating, carrying out photoetching and development and making a pattern with a specific shape on the monitoring pattern; C. etching the substrate for a certain time by oxygen or oxygen containing plasma; D. observing the monitoring pattern under an optical microscope; and E. repeating steps C and D until emitter metal, basal poles and collector binding posts are exposed. The invention carries out the processes of making the monitoring pattern and devices simultaneously without additional technical processes, reduces the monitoring difficulty, improves the monitoring precision, avoids costs of complicated equipment, effectively saves costs, can accurately monitor the planarization process, stabilizes the process and avoids the process instability caused by over etching or under etching.

Description

technical field [0001] The invention relates to the technical field of III-V semiconductor heterojunction bipolar transistor (Heterojunction Bipolar Transistor, HBT) device manufacturing technology, in particular to a method for monitoring the dielectric planarization process, so as to solve the problem of the lead-out and interconnection of small-sized electrodes Planarization process issues in junctions. Background technique [0002] With the development of HBT technology, the size of the HBT emitter is getting smaller and smaller, and the existing technology using micro-air bridges can no longer meet the requirements of HBT in terms of small size and low parasitic. At this time, the entire process must adopt planarization technology. That is to use the medium to bury the metal of the base and collector below, and expose the contact part above the medium. [0003] The emitter metal is higher, while the base and collector metals are placed about 1 micron lower than the em...

AI Technical Summary

Problems solved by technology

Although this method avoids damage to the sample during electron microscope observation, the monitoring is very inaccurate, often resulting in over-etching or under-etching of the medium, resulting in low repeatability and poor yield in device manufacturing.

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