A substrate for mounting an optical component includes a first groove
formed in a surface of a substrate, a second groove formed in the surface
of the substrate, the second groove having a depth greater than the first
groove. In the present invention, the first groove and the second groove
are related to each other by the following equation,
(2D sin .theta.)/R.gtoreq.C
where D denotes a depth of the first groove, .theta. denotes an angle
between a horizontal plane and a slanted surface of the first groove
(0.degree.<.theta.<90.degree.), R=F/E (E denotes an etching rate of
a slanted surface of the first groove, F denotes an etching rate of a
bottom surface of the groove, C denotes a top opening width of the groove.
The first and second grooves are formed by forming a protection film on an
entire top surface of the substrate, forming pattern holes corresponding
to the first and second grooves in the protection film by a single mask
having holes corresponding to the first and second grooves, forming a
protection seal on a pattern hold corresponding to one of the first and
second grooves, applying anisotropic etching to the substrate through the
not-sealed pattern hole to thereby form the other of the first and second
grooves, removing the protection seal, forming another protection seal on
the groove formed by anisotropic etching, applying anisotropic etching to
the substrate through the seal-removed pattern hole to thereby form the
remaining one of the first and second grooves; and removing the protection
film and the another protection seal from the substrate.
Un substrato per il montaggio del componente ottico include una prima scanalatura formata in una superficie di un substrato, una seconda scanalatura formata nella superficie del substrato, la seconda scanalatura che ha una profondità più grande della prima scanalatura. Nella presente invenzione, la prima scanalatura e la seconda scanalatura sono riferite l'un l'altro dalla seguente equazione, (il 2D theta.)/R.gtoreq.C in cui la D denota una profondità della prima scanalatura, theta. di sin denota un angolo fra un piano orizzontale e una superficie fatta pendere della prima scanalatura (0.degree.