Pattern for monitoring epitaxial layer washout

摘要

A pattern for monitoring epitaxial layer washout is disclosed. The pattern includes first and second sub-patterns. The first sub-pattern has a shape and defines one or more minimum dimensions. Obfuscation of the first sub-pattern means that epitaxial washout has occurred at least for dimensions equal to or less than the minimum dimensions. The second sub-pattern has the same shape of the first sub-pattern, but defines one or more maximum dimensions. Obfuscation of the second sub-pattern means that epitaxial washout has occurred for dimensions equal to or less than the maximum dimensions. The sub-patterns can include a pair of separated features, such as a pair of interlocking but separated L-shaped features, the separation of which defines the dimensions of the sub-patterns.