Patent ID: 7348186

Claim:
A method of improving a semiconductor substrate including a SiGe film on a Si or SOI substrate, the method including determining a relationship between a film condition of the SiGe film and a hydrogen ion implantation condition used in making the SiGe film so as to achieve relaxation of lattice distortion in the SiGe film as well as improved crystallinity and/or surface condition of the SiGe film, so that improved conditions for improving quality of the SiGe film on the Si or SOI substrate can be determined, the method comprising: experimentally determining improvement conditions for making the semiconductor substrate so as to improve relaxation of lattice distortion in the SiGe film and to improve crystallinity and/or surface condition of the SiGe film, by using the following parameters (1), (2) and (3), (1) an elastic strain energy U SiGe which depends on a Ge concentration of the SiGe film and on a thickness of the SiGe film, (2) a peak depth Rp which is a distance between a SiGe/Si interface and a peak position of hydrogen ion concentration in the Si or SOI substrate and which depends on a hydrogen ion implantation energy and on the thickness of the SiGe film, and (3) an amount of hydrogen ions to be implanted; determining an amount of hydrogen ions to be implanted and a hydrogen ion implantation energy for the SiGe film based on parameters (1), (2) and (3), and performing the hydrogen ion implantation in the SiGe film based on the determined ion implantation conditions; and wherein the hydrogen ion implantation comprises: (a) calculating elastic strain energy U SiGe from both the Ge concentration and the thickness of the SiGe film; (b) setting an optional amount of hydrogen ions to be implanted and hydrogen ion implantation energy, respectively; (c) calculating the peak depth Rp from both the thickness of the SiGe film and the set hydrogen ion implantation energy; and (d) determining the amount of hydrogen ions as the parameter (3) and ion implantation energy of hydrogen ions to be implanted, respectively, if the calculated hydrogen ion implantation energy, the calculated the peak depth Rp and the set amount of hydrogen ions to be implanted are in a predetermined range as the experimentally determining improvement conditions by using the parameters (1), (2) and (3).