(JP10135500-A)      The method involves forming a multi-layered porous layer (12) on a semiconductor base (1). The porous degree of the porous layer and the base varies from each other. A semiconductor film (13) is formed on the porous layer. The semiconductor film is peeled out from the base through the porous layer.    ADVANTAGE -   Excels in crystallinity. Reduces power consumption.    (US6107213-A)      The method comprises providing a semiconductor substrate (11) with a surface, and anodizing the substrate to provide a first porous layer (12S) adjacent the surface having a first porosity. A second anodization step is performed at a second higher current density to provide at least one second porous layer (12H) adjacent the first porous layer opposite the surface having a porosity greater than the first porosity. Preferably, a third anodization step at a third higher current density is performed to define a third porous layer having a third porosity higher than the second porosity.    The difference in porosity between the porous layers provides an inherent line or zone of weakness located in the porous structure. A semiconductor thin film (13) is then grown on the surface and first porous layer. The grown film is separated from the semiconductor substrate along the line of weakness to provide the intended thin film semiconductor. The separated thin fill attached to the support substrate may be further processed to provide improved film products, solar panels and light emitting diode devices.    USE/ADVANTAGE -   For window glass equipped with solar cells, solar car, etc. Provides solar cell which has large surface area, excellent crystallinity, and sufficient thinness can be cheaply produced.    (US6194239-B1)      The method comprises providing a semiconductor substrate (11) with a surface, and anodizing the substrate to provide a first porous layer (12S) adjacent the surface having a first porosity. A second anodization step is performed at a second higher current density to provide at least one second porous layer (12H) adjacent the first porous layer opposite the surface having a porosity greater than the first porosity. Preferably, a third anodization step at a third higher current density is performed to define a third porous layer having a third porosity higher than the second porosity.    The difference in porosity between the porous layers provides an inherent line or zone of weakness located in the porous structure. A semiconductor thin film (13) is then grown on the surface and first porous layer. The grown film is separated from the semiconductor substrate along the line of weakness to provide the intended thin film semiconductor. The separated thin fill attached to the support substrate may be further processed to provide improved film products, solar panels and light emitting diode devices.    USE/ADVANTAGE -   For window glass equipped with solar cells, solar car, etc. Provides solar cell which has large surface area, excellent crystallinity, and sufficient thinness can be cheaply produced.    (US6194245-B1)      The method comprises providing a semiconductor substrate (11) with a surface, and anodizing the substrate to provide a first porous layer (12S) adjacent the surface having a first porosity. A second anodization step is performed at a second higher current density to provide at least one second porous layer (12H) adjacent the first porous layer opposite the surface having a porosity greater than the first porosity. Preferably, a third anodization step at a third higher current density is performed to define a third porous layer having a third porosity higher than the second porosity.    The difference in porosity between the porous layers provides an inherent line or zone of weakness located in the porous structure. A semiconductor thin film (13) is then grown on the surface and first porous layer. The grown film is separated from the semiconductor substrate along the line of weakness to provide the intended thin film semiconductor. The separated thin fill attached to the support substrate may be further processed to provide improved film products, solar panels and light emitting diode devices.    USE/ADVANTAGE -   For window glass equipped with solar cells, solar car, etc. Provides solar cell which has large surface area, excellent crystallinity, and sufficient thinness can be cheaply produced.