Crystal growth method and semiconductor device manufacturing method
A crystal growth method of the present disclosure includes: preparing a substrate having a surface layer; forming a mask pattern including a plurality of strip bodies on the surface layer to separate the surface layer into segments by the plurality of strip bodies and expose part of the surface layer; and forming, on a plurality of growth regions constituted by the exposed part of the surface layer, a crystal growth-derived layer by causing a semiconductor crystal which differs in lattice constant from the substrate to grow by a vapor-phase growth process. Each of the plurality of strip bodies has side faces inclined so that a width between the side faces gradually decreases with distance from the surface layer.
1. A semiconductor device manufacturing method, comprising:
forming a crystal growth-derived layer by a crystal growth method comprising:
preparing a substrate having a surface layer;
forming a mask pattern including a plurality of strip bodies on the surface layer to separate the surface layer into segments by the plurality of strip bodies and expose part of the surface layer; and
forming, on a plurality of growth regions constituted by the exposed part of the surface layer and on upper surfaces of the plurality of strip bodies, a crystal growth-derived layer by causing a semiconductor crystal which differs in lattice constant from the substrate to grow by a vapor-phase growth process;
each of the plurality of strip bodies having side faces inclined so that a width between the side faces gradually decreases with distance from the surface layer,
wherein, in forming the crystal growth-derived layer, growth of the crystal growth-derived layer is stopped before adjacent crystal growth derived layers contact each other;
forming, on the crystal growth-derived layer, a semiconductor layer, wherein, in forming the semiconductor layer, growth of the semiconductor layer is stopped before adjacent semiconductor layers contact each other;
removing the mask pattern by etching; and
forming a plurality of semiconductor devices after removing the mask pattern, by dividing the substrate such that each of the plurality of semiconductor devices includes the crystal growth-derived layer and the semiconductor layer.
2. The semiconductor device manufacturing method according to claim 1 , wherein the strip body has a trapezoidal or triangular transverse section.
3. The semiconductor device manufacturing method according to claim 1 , wherein the mask pattern has a striped configuration or a lattice configuration.
4. The semiconductor device manufacturing method according to claim 1 , wherein the plurality of semiconductor devices are not coupled.
5. The semiconductor device manufacturing method according to claim 1 , wherein
in forming the semiconductor layer a first formula is satisfied,
the first formula is W/2−(D−t)×n>t/tan α,
D is a thickness of the crystal growth-derived layer,
t is a height of one of the plurality of strip bodies,
W is a width of a bottom side of the one of the plurality of strip bodies, the bottom side being in connection with the substrate,
n is a ratio of a growing rate in the planar direction to a growing rate in the direction normal to the substrate, and
α is an angle formed between the side faces of the one of the plurality of strip bodies and the substrate.
6. The semiconductor device manufacturing method according to claim 1 , wherein the plurality of semiconductor devices are formed after the mask pattern is removed.