Asymmetric triangular grating profiles with 90 degrees groove angles produced by ion-beam erosion.

A simple phenomenological model has been developed to account for the effects of redeposition during transverse ion-beam erosion of grating relief patterns on surfaces. The model predicts the evolution with time of an inclined facet in the substrate, and the dependence of the facet angle theta(r) on angle of incidence of the ion beam, erosion rates of mask and substrate, and the geometrical parameters of the mask. The results are illustrated by calculation of the angular dependence of theta(r) for AZ-1350 photoresist masks on GaAs and SiO(2) substrates and for Ti on SiO(2). A strong dependence of theta(r) on mask intercept angle alpha is found, except for a limited range in angle of incidence of the ion beam. Combined with results derived previously, the facet angles theta(S) and theta(r) and the groove angle theta(g) of the asymmetric triangular groove profiles produced in these systems have been determined. A groove angle of 90 degrees cannot be obtained for AZ-1350 on GaAs and SiO(2), but in appropriate conditions a 90 degrees groove angle may be obtained in SiO(2) with a Ti mask.

[1]  A. Bayly.  Secondary processes in the evolution of sputter-topographies , 1972 .

[2]  H. Casey,et al.  Dry processing of high resolution and high aspect ratio structures in GaAs-Al(x)Ga(1-x) As for integrated optics. , 1977, Applied optics.

[3]  M. Feuer,et al.  Fabrication of 300‐Å metal lines with substrate‐step techniques , 1980 .

[4]  Susumu Namba,et al.  Blazed Ion-etched Holographic Gratings , 1976 .

[5]  Kazuo Sano,et al.  High spectroscopic qualities in blazed ion-etched holographic gratings , 1979 .

[6]  E. Loewen,et al.  Grating efficiency theory as it applies to blazed and holographic gratings. , 1977, Applied optics.

[7]  Per G. Glöersen.  Ion Beam Etching , 1975, Atomic Layer Processing.

[8]  L. Johnson,et al.  Evolution of grating profiles under ion-beam erosion. , 1979, Applied optics.

[9]  Henry I. Smith,et al.  Oriented crystal growth on amorphous substrates using artificial surface‐relief gratings , 1978 .

[10]  Dimitri A. Antoniadis,et al.  Graphoepitaxy of silicon on fused silica using surface micropatterns and laser crystallization , 1979 .

[11]  L. Johnson,et al.  Interference gratings blazed by ion‐beam erosion , 1979 .

[12]  Michael W. Geis,et al.  Crystallographic orientation of silicon on an amorphous substrate using an artificial surface‐relief grating and laser crystallization , 1979 .

[13]  M. W. Thompson,et al.  Microtopography of surfaces eroded by ion-bombardment , 1969 .

[14]  D. Nobili,et al.  Observation of the slip bands and glide planes in aluminium/alumina alloys (SAP) , 1969 .

[15]  Robert E. Lee.  Microfabrication by ion‐beam etching , 1979 .

[16]  M. Cantagrel,et al.  Development of a general surface contour by ion erosion. Theory and computer simulation , 1974 .

[17]  L. Johnson,et al.  An oblique shadow deposition technique for altering the profile of grating relief patterns on surfaces , 1979 .

[18]  R. McPhedran,et al.  Blaze Optimization for Triangular Profile Gratings , 1973 .