Article

Abstract

• We describe the design of a common-path heterodyne laser interferometer for the surface profiling of micron-sized photopatterned features during the microelectronic fabrication process. The common-path design of the interferometer’s reference and measurement arms effectively removes any path length difference in the measurement which can be attributed to the movement of the target surface. It is shown that repeated surface profiling during the ion milling process allows the difference in etch rates between the photoresist layer and the exposed portions of the underlying substrate layer to be monitored online. A prototype apparatus has been assembled and results demonstrating the usefulness of the device are reported. The surface profiles of both a photopatterned nickel–iron trench and an unmasked aluminum trench are measured and compared to those obtained using a stylus-based scanning profiler and an atomic force microscope.

Creator

• Klein, Eric J.
• Hall, John L.
• Ramirez, Fred

Date Issued

• 2001-03-01

Academic Affiliation

• Physics

Journal Title

• Review of Scientific Instruments

Journal Issue/Number

• 5

Journal Volume

• 72

File Extent

• 2455-2466

Last Modified

• 2019-12-05

Resource Type

• Article

Rights Statement

• In Copyright

DOI

• 10.1063/1.1367353

ISSN

• 0034-6748

Language

• English [eng]

Relationships

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