Semiconductor base material and method of manufacturing the material

摘要

As shown in Fig. 1(a), substrate 1 having a growth plane having a concavo-convex surface is used. When GaN group crystal is vapor phase grown using this substrate, the concavo-convex shape suppresses growth in the lateral direction and promotes growth in the C axis direction, thereby affording a base surface capable of forming a facet plane. Thus, as shown in Fig. 1(b), a crystal having a facet plane is grown in a convex part, and a crystal is also grown in a concave part. When the crystal growth is continued, the films grown from the convex part and the concave part are joined in time to cover a concavo-convex surface and become flat as shown in Fig. 1(c). In this case, an area having a low a dislocation density is formed in the upper part of the convex part where facet plane was formed, and the prepared film has high quality.