Appeal No. 1999-2580 Page 2
Application No. 08/753,598
provides a sharp optical absorption spectrum. In particular, the degree of quantum
mechanical coupling increases significantly by setting the thickness of the intermediate
layer to be smaller than the height of the freely-grown quantum dot.
Representative independent claim 1 is reproduced as follows:
1. A quantum semiconductor device, comprising:
a semiconductor substrate;
an active layer formed on said semiconductor substrate and including a
quantum structure;
said quantum structure comprising:
a plurality of intermediate layers stacked on each other repeatedly, each
of said plurality of intermediate layers having a substantially flat top surface and
being formed on a first semiconductor crystal having a first lattice constant;
each of said intermediate layers including a plurality of quantum dots of a
second semiconductor crystal having a second lattice constant different from
said first lattice constant, said second semiconductor crystal forming thereby a
strained system with respect to said first semiconductor crystal, each of said
quantum dots in an intermediate layer having a height substantially identical with
a thickness of said intermediate layer, and each of said intermediate layers has a
thickness smaller than a height of said quantum dots in a freely grown state;
said quantum dot in an intermediate layer aligning with another quantum
dot in an adjacent intermediate layer in a direction perpendicular to a principal
surface of said semiconductor substrate;
each of said plurality of intermediate layers having a thickness equal to or
smaller than a Bohr-radius of carriers in said intermediate layer.
The examiner relies on the following references:
Sakai et al. (Sakai) 4,992,837 Feb. 12, 1991
Wallace et al. (Wallace) 5,606,177 Feb. 25, 1997
(Filed Dec. 6, 1994)
Xie et al. (Xie), “Vertically Self-Organized InAs Quantum Box Islands on GaAs(100),”
Physical Review Letters, Vol. 75, No. 13, pp. 2542-2545 (1995)
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