Chemical Mechanical Polish in the Growth of Semiconductor Regions

摘要

A method includes performing a first planarization step to remove portions of a semiconductor region over isolation regions. The first planarization step has a first selectivity, with the first selectivity being a ratio of a first removal rate of the semiconductor region to a second removal rate of the isolation regions. After the isolation regions are exposed, a second planarization step is performed on the isolation regions and a portion of the semiconductor region between the isolation regions. The second planarization step has a second selectivity lower than the first selectivity, with the second selectivity being a ratio of a third removal rate of the portion of semiconductor region to a fourth removal rate of the isolation regions.

主权项

1. A method comprising:
performing a first planarization step to remove portions of a semiconductor region over isolation regions, wherein the first planarization step has a first selectivity, with the first selectivity being a ratio of a first removal rate of the semiconductor region to a second removal rate of the isolation regions, wherein the first planarization step is finished after the isolation regions are exposed; and after the isolation regions are exposed, performing a second planarization step on the isolation regions and a portion of the semiconductor region between the isolation regions, wherein the second planarization step has a second selectivity lower than the first selectivity, with the second selectivity being a ratio of a third removal rate of the portion of the semiconductor region to a fourth removal rate of the isolation regions.