Semiconductor photo-detecting device

1. A photo-detecting device, comprising:

a substrate ( 100 );

a first semiconductor layer ( 101 ) located on the substrate ( 100 ) and having a first dopant;

a second semiconductor layer ( 104 ) located on the first semiconductor layer ( 101 ) and having a first region ( 104 a ) and a second region ( 104 b ), wherein the first region ( 104 a ) has a first perimeter ( 104 a 1 ) and comprises a second dopant and a third dopant, and the second region ( 104 b ) comprises the second dopant and does not comprise the third dopant;

a light-absorbing layer ( 102 ) located between the first semiconductor layer ( 101 ) and the second semiconductor layer ( 104 ), and having a third region ( 102 a ) and a fourth region ( 102 b ), wherein the third region ( 102 a ) comprises the third dopant, and the fourth region ( 102 b ) does not comprise the third dopant; and

a semiconductor contact layer ( 106 ) contacting the first region; and

an electrode structure ( 108 ) located on the semiconductor contact layer ( 106 ) and having an outer sidewall ( 108 c ) aligned with the first perimeter ( 104 a 1 ),

wherein the semiconductor contact layer 006 ) has a first thickness greater than 50 Å and smaller than 1000 Å, and

wherein the second semiconductor layer ( 104 ) further comprises a fifth region ( 104 c ) located between the first region ( 104 a ) and the second region ( 104 b ), and the fifth region ( 104 c ) comprises the third dopant and is located beyond the outer sidewall ( 108 c ) in a horizontal direction.

2. The photo-detecting device of claim 1 , wherein the semiconductor contact layer ( 106 ) comprises a first side surface ( 306 ) and a second side surface ( 406 ) opposite to the first side surface ( 306 ), and the second side surface ( 406 ) is separated from the first perimeter ( 104 a 1 ) in the horizontal direction by a distance ranging from 1 μm to 20 μm.

3. The photo-detecting device of claim 2 , wherein the electrode structure ( 108 ) covers the second side surface ( 406 ) without covering the first side surface ( 306 ).

4. The photo-detecting device of claim 1 , wherein the semiconductor contact layer ( 106 ) has a first part with a third width and a second part with a four width larger than the third width.

5. The photo-detecting device of claim 1 , wherein the third region ( 102 a ) has a third thickness of 0.1 μm to 1 μm.

6. The photo-detecting device of claim 1 , wherein the first region ( 104 a ) or the fifth region ( 104 c ) has a conductivity-type different from that of the second region ( 104 b ).

7. The photo-detecting device of claim 1 , wherein the first region ( 104 a ) and the third region ( 102 a ) have a depth (D 1 ) and the fifth region ( 104 c ) has a first width (W 21 ), and a ratio of the depth (D 1 ) to the first width (W 21 ) is greater than 0.67 and smaller than 2.

8. The photo-detecting device of claim 7 , wherein the depth ( 31 ) is from 2 μm to 4 μm.

9. The photo-detecting device of claim 7 , wherein the first width (W 21 ) is from 2 μm to 3 μm.

10. The photo-detecting device of claim 1 , wherein the third dopant in the second semiconductor layer ( 104 ) has a first diffusion coefficient and the third dopant in the light-absorbing layer ( 102 ) has a second diffusion coefficient smaller than the first diffusion coefficient.

11. The photo-detecting device of claim 1 , wherein the third dopant is different from the second dopant, and the third dopant in the first region ( 104 a ) has a first concentration and the second dopant in the first region ( 104 a ) has a second concentration less than the first concentration.

12. The photo-detecting device of claim 1 , further comprising an interlayer ( 105 ) between the light absorbing layer ( 102 ) and the first semiconductor layer ( 101 ).

13. The photo-detecting device of claim 12 , wherein the interlayer ( 105 ) is an undoped semiconductor layer.

14. The photo-detecting device of claim 12 , wherein the interlayer ( 105 ) has a second thickness of 0.5 μm-3 μm.

15. The photo-detecting device of claim 12 , wherein the interlayer ( 105 ) has an energy band gap larger than that of the light-absorbing layer ( 102 ).

16. The photo-detecting device of claim 1 , further comprising an insulating layer ( 107 ) located on the second semiconductor layer ( 104 ), wherein the second region ( 104 b ) has a portion not covered by the electrode structure ( 108 ) and the insulating layer ( 107 ), and the portion has a second width ranging from 10 μm to 100 μm.

17. The photo-detecting device of claim 1 , wherein the third region ( 102 a ) has a second perimeter ( 102 a 1 ) aligned with the outer sidewall ( 108 c ).

18. The photo-detecting device of claim 17 , wherein the light-absorbing layer ( 102 ) further comprises a sixth region ( 102 c ) located between the third region ( 102 a ) and the fourth region ( 102 b ), and the sixth region ( 102 c ) comprises the third dopant and is located diffusing from the third region beyond the outer sidewall ( 108 c ) in the horizontal direction.

19. The photo-detecting device of claim 1 , further comprising a diffusion barrier layer ( 103 ) located between the second semiconductor layer ( 104 ) and the light-absorbing layer ( 102 ).

20. A photo-detecting module, comprising:

a light-emitting device ( 20 );

the photo-detecting device ( 10 ) of claim 1 ; and

a carrier ( 30 ) electrically connecting to the light-emitting device ( 20 ) and the photo-detecting device ( 10 ).