| 摘要 |
PURPOSE:To perform high concentration doping with B with good controllability so as to exceed the limit of solid solution, in doping with B (boron) in an Si molecular beam growing technology, by projecting Ge whose amount is larger than that of the B onto a substrate. CONSTITUTION:The atomic radius of B is 0.98 Angstrom and smaller than the atomic radius 132 Angstrom of Si. Therefore, when the B is independently introduced in Si crystals at a high concentration, strain is yielded in a shape the lattice is contracted, and a film having excellent crystal property is not obtained. In order to allevaite the strain of the Si crystals due to the doping with B, the adequate amount of Ge, which is a group IV element and has a larger radius than those of B and Si, is simultaneously introduced so that the strain due to the doping of the B is allevaited. The crystal property of an epitaxial film, in which the B is doped at a high concentration, is improved by simultaneously doping the B and the Ge, which is more than the amount of B. The doping exceeding the limit of the solid solution of the B can be performed. A higher activating rate can be also obtained.
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