Semiconductor substrate having a partial SOI structure, method of manufacturing the same, a semiconductor device having a partial SOI structure, and method of manufacturing the same
A semiconductor substrate is disclosed which comprises a first single crystal silicon layer, an insulator formed to partially cover one main surface of the first single crystal silicon layer, a second single crystal silicon layer formed to cover a region of the first single crystal silicon layer which is not covered with the insulator, and to cover an edge portion of the insulator adjacent to the region, and a non-single crystal silicon layer formed on the insulator, the interface between the non-single crystal silicon layer and the second single crystal silicon layer being positioned on the insulator.
1. A semiconductor substrate having a non-insulator region and an insulator region structure, comprising:
a first single crystal silicon layer formed in the non-insulator region, including a first surface;
a second single crystal silicon layer formed in the insulator region, including a second surface being flush with the first surface;
an insulator formed under the second single crystal silicon layer; and
a non-single crystal silicon layer formed only under the insulator, an end of an interface between the insulator and the non-single crystal silicon layer by a side of the non-insulator region being separated from an end of the insulator by the side of the non-insulator region with a predetermined distance.
2. A semiconductor substrate according to claim 1 , further comprising:
a third single crystal silicon layer formed under the insulator so as to cover the non-single crystal silicon layer.
3. A semiconductor substrate according to claim 1 , wherein the non-single crystal silicon layer is a polycrystalline silicon layer.
4. A semiconductor device having a partial silicon on insulator structure, comprising:
a semiconductor substrate including a non-insulator region and an insulator region;
the non-insulator region including a first single crystal silicon layer having a first surface;
the insulator region including a second single crystal layer having a second surface, an insulator formed under the second single crystal layer and a non-single crystal silicon layer formed only under the insulator;
a first semiconductor element formed on the first surface, including a first source/drain and a first gate; and
a second semiconductor element formed on the second surface, including a second source/drain and a second gate.
5. A semiconductor device according to claim 4 , wherein an end of an interface between the insulator and the non-single crystal silicon layer by a side of the non-insulator region is separated from an end of the insulator by the side of the non-insulator region with a predetermined distance.
6. A semiconductor device according to claim 4 , wherein the first surface is flush with the second surface.
7. A semiconductor device according to claim 4 , wherein the first semiconductor element includes a trench capacitor.