Bipolar transistor and manufacturing method thereof

A bipolar transistor manufacturing method, comprising:

• a first process for forming a first insulating film on the surface of first conductive type of silicon;
• a second process for forming a second conductive type of polycrystal layer having a reverse conductive type to a first conductive type on the first insulating film;
• a third process for forming a second insulating film on the second conductive type of polycrystal layer;
• a fourth process for forming an opening by etching the first insulating film, the second conductive type of polycrystal layer and the second insulating film;
• a fifth process for forming a first single crystal silicon germanium layer of a second conductive type on the surface of the first conductive type of silicon in the opening;
• a sixth process for forming a second single crystal silicon germanium layer of the second conductive type on the first single crystal silicon germanium layer of the second conductive type;
• a seventh process for forming a second conductive type of polycrystalline silicon germanium layer so that it is in contact with the second single crystal silicon germanium layer of the second conductive type and the second conductive type of polycrystal layer;
• an eighth process for forming a first single crystal area of the first conductive type on the second single crystal silicon germanium layer of the second conductive type;
• and
• a ninth process for forming a second single crystal area of the first conductive type including a part of the first single crystal silicon germanium layer of the second conductive type.