Photodiode and manufacturing method thereof
A photodiode comprises a substrate, a first collection layer, a first type well layer, a second type well layer and a second collection layer. The substrate has a first surface and a second surface. The substrate defines a bias region and a signal region. The first collection layer, the first type well layer, the first type well layer, the second type well layer, and the second collection layer are formed in the substrate. The first type well layer is disposed between the first surface and the first collection layer. The second type well layer is disposed between the first type well layer and the first collection layer. The second collection layer is located between the first surface and the second well layer.
1 . A manufacturing method for a photodiode, comprising:
providing a substrate, wherein the substrate has a first surface and a second surface opposite to the first surface, the substrate defines a bias region, a ground region and a signal region;
forming a first collection layer in the substrate by using a first semiconductor material, wherein the first collection layer is located within the bias region and the signal region;
forming a first type well layer in the substrate, wherein the first type well layer disposed between the first surface and the first collection layer is located within the bias region;
forming a second type well layer in the substrate, wherein the second type well layer disposed between the first type well layer and the first collection layer is located within the bias region and signal region;
forming a groove exposing the first type well layer on the first surface of the substrate; and
forming a second collection layer in the groove of the substrate by using a second semiconductor material.
2 . The manufacturing method for the photodiode of claim 1 , wherein the second semiconductor material includes germanium, silicon germanium or the combination thereof.
3 . The manufacturing method for the photodiode of claim 1 , further comprising:
forming a semiconductor material ground layer in the substrate, wherein the semiconductor material ground layer is located within the ground region.
4 . The manufacturing method for the photodiode of claim 1 , further comprising:
forming a semiconductor material connection layer in the substrate, wherein the semiconductor material connection layer located within the signal region is physically connected with the second type well layer.
5 . The manufacturing method for the photodiode of claim 1 , further comprising:
forming a semiconductor material insulator layer in the substrate, wherein the semiconductor material insulator layer is located between the signal region and the ground region.