Patent ID: 6888261
Filing Date: 2005-05-03
Classification: H01L,Y10S

Abstract:
1. An alignment mark in which a plurality of at least one of mesa and trench type unit marks are aligned with a predetermined gap therebetween in an underlying layer to which a chemical mechanical polishing process is applied so that alignment signals are formed during an alignment process, wherein: each of the mesa and trench type unit marks includes at least one or more of mesa and trench patterns, the mesa or trench patterns within each mesa or trench type unit mark being spaced sufficiently close together to prevent a dishing phenomenon during a chemical mechanical polishing process; the pattern pitch P′ of the mesa and trench pattern formed within the mesa and trench unit marks is given by the formula P′=P/(2n′+1) ±0.05 μm (n′: natural number); and P sin θ=nλ, P is pitch between unit marks, λ is wavelength of a first probing beam illuminating the unit marks, θ is diffraction angle, n′ is the number of mesa or trench patterns, n is diffraction order of the first probing beam illuminating the unit marks, λ′ is wavelength of a second probing beam for illuminating the mesa or trench patterns, 2n′+1 is diffraction order by the wavelength λ′ of the second probing beam.