Abstract: A method for manufacturing a strained silicon wafer, having steps of a first step of preparing a single crystal silicon substrate, a second step of forming a graded SiGe layer on the substrate, the graded SiGe layer having a first Ge composition ratio increased stepwisely from 5 to 60% at atomic ratio, a third step of forming a SiGe constant composition layer on the graded SiGe layer, the SiGe constant composition layer having a Ge composition ratio substantially equal to the Ge composition ratio on a surface of the-graded SiGe layer and a fourth step of forming a strained Si layer on the SiGe constant composition layer. The second through fourth steps are performed under the reduced pressure atmosphere while the single crystal silicon substrate is rotated in a circumferential direction at a rate from 300 rpm to 1500 rpm.

Abstract: This invention provides a cleaning method of silicon wafer for obtaining a silicon wafer in which micro roughness thereof under spatial frequency of 20/?m is 0.3 to 1.5 nm3 in terms of power spectrum density, by passing a process of oxidizing the silicon wafer with ozonized water and a process of cleaning said oxidized silicon wafer with hydrofluoric acid. Consequently, it is possible to remove surface adhering pollutant such as particles and metallic foreign matter with the surface structure of silicon wafer flattened up to atomic level by annealing maintained.

Abstract: A manufacturing method for a silicon substrate having a strained layer, has steps of forming a plurality of atomic steps having a height of 0.1 nm or more on the surface of a silicon substrate, forming a plurality of terraces having a width of 0.1 ?m or more between the plurality of atomic steps and forming a SiGe layer or a SiGe layer and a Si layer on the silicon substrate.

Abstract: A method for manufacturing a strained silicon wafer, having steps of a first step of preparing a single crystal silicon substrate, a second step of forming a graded SiGe layer on the substrate, the graded SiGe layer having a first Ge composition ratio increased stepwisely from 5 to 60% at atomic ratio, a third step of forming a SiGe constant composition layer on the graded SiGe layer, the SiGe constant composition layer having a Ge composition ratio substantially equal to the Ge composition ratio on a surface of the-graded SiGe layer and a fourth step of forming a strained Si layer on the SiGe constant composition layer. The second through fourth steps are performed under the reduced pressure atmosphere while the single crystal silicon substrate is rotated in a circumferential direction at a rate from 300 rpm to 1500 rpm.

Abstract: A manufacturing method for a silicon substrate having a strained layer, has steps of forming a plurality of atomic steps having a height of 0.1 nm or more on the surface of a silicon substrate, forming a plurality of terraces having a width of 0.1 &mgr;m or more between the plurality of atomic steps and forming a SiGe layer or a SiGe layer and a Si layer on the silicon substrate.

Abstract: This invention provides a cleaning method of silicon wafer for obtaining a silicon wafer in which micro roughness thereof under spatial frequency of 20/&mgr;m is 0.3 to 1.5 nm3 in terms of power spectrum density, by passing a process of oxidizing the silicon wafer with ozonized water and a process of cleaning said oxidized silicon wafer with hydrofluoric acid. Consequently, it is possible to remove surface adhering pollutant such as particles and metallic foreign matter with the surface structure of silicon wafer flattened up to atomic level by annealing maintained.