Infrared Reflection Method to Measure Subcollector Flat Region Depth
Original Publication Date: 1980-Oct-01
Included in the Prior Art Database: 2005-Feb-13
It is crucial in shallow device epitaxial structures to achieve tight tolerances on the vertical dopant profiles. Moreover, it is desirable to monitor such profiles early in the process cycle rather than upon completion of the devices so that unacceptable device wafers may be screened out to save needless processing expense. Vertical dopant profile is monitored by measuring the depth of the subcollector flat region before the device is completed.