The BGM300 was designed to enable quick and accurate measurement of Through Si Via (TSV) depths, Si wafer thickness, and Remaining Si Thickness (RST) above TSVs – all essential in a managed backside via reveal process flow. Back grinding errors due to “blind” grinding can lead to significant yield loss.
During the back grinding process to reveal the TSV, it is extremely important to stop grinding a few microns above the Via and then use an etching (dry/wet) process to expose the conducting material. If the remaining Si is left too thick, the etching process will be long and reduce throughput. On the other hand, if over-grinding occurs when Cu is used for the TSVs, Cu contamination of the back side of the wafer will be the consequence. Furnished with state-of-the-art proprietary IR optics and a novel interferometer, the BGM300 has enabled customers to overcome many challenges associated with the TSV reveal process and many other critical processes needed in 3DIC manufacturing.