| 摘要 |
PURPOSE:To obtain an epitaxial layer scarecely generating autodoping by forming a first epitaxial layer of the thickness of the degree enough to suppress the issue of impurity atoms into a treating atmosphere, raising the temperature of a semiconductor substrate with only carrier gas flowed, lowering the temperature again and forming a second epitaxial growth layer. CONSTITUTION:A semiconductor substrate 11 having high impurity density is heated up to the fixed epitaxial growth temperature, for example, 1,050 deg.C and reactive gas composed of SiH2Cl2 or the like is supplied to H2 carrier gas of 50l per min. at the rate of, for example, 200cc per min. to form a first epitaxial layer 12 of the thickness of 0.3Xm. The temperature of the semiconductor substrate 11 is raised up to, for example, 1,100 deg.C and held with H2 gas flowed. Again, the temperature of the semiconductor substrate 11 is lowered to the epitaxial growth temperature 1,050 deg.C and reactive gas composed of SiH2Cl2 and PH3 determining conductivity and resistivity of the epitaxial growth layer and the like are supplied to the H2 carrier gas, thereby forming the second epitaxial layer 16 at the fixed thickness for example, 3.7mum. |
