Photodetection device and manufacturing method thereof

Abstract

A photodetection device and a manufacturing method are provided. The photodetection device includes an absorption structure, a cathode, a charge multiplication region and an anode. The absorption structure is formed in a recess at a surface region of a semiconductor substrate, and configured to receive an incident light. The cathode is formed on a top surface of the absorption structure, and has a first conductive type. The charge multiplication layer is in lateral contact with the absorption structure, and is an intrinsic portion of the semiconductor substrate extending into the semiconductor substrate from a topmost surface of the semiconductor substrate. The anode is in lateral contact with the charge multiplication layer from a side of the charge multiplication region away from the absorption structure, and is a doped region in the semiconductor substrate having a second conductive type complementary to the first conductive type.

What is claimed is: 
     
         1 . A method for manufacturing a photodetection device, comprising:
 performing an ion implantation process to form a charge region into a semiconductor substrate, wherein the charge region has a first conductive type;   performing an ion implantation process to form an anode with a second conductive type into the semiconductor substrate, wherein the anode is laterally spaced apart from the charge region, and a portion of the semiconductor substrate in between the charge region and the anode defines a charge multiplication region;   forming a recess into the charge region, such that the charge region is shaped into a charge layer defining the recess;   forming an absorption structure in the recess;   forming a capping material layer covering the absorption structure and the charge layer; and   performing an ion implantation process to form a cathode with the first conductive type into the capping material layer, wherein the cathode is in contact with the absorption structure, and remained portions of the capping material layer define a capping layer entirely covering topmost surfaces of the charge layer.   
     
     
         2 . The method for manufacturing the photodetection device according to  claim 1 , wherein the anode, the charge layer and the absorption structure are each formed in a line shape, and are substantially parallel with one another. 
     
     
         3 . The method for manufacturing the photodetection device according to  claim 1 , further comprising:
 patterning the semiconductor substrate to form a waveguide directly in lateral contact with the absorption structure.   
     
     
         4 . The method for manufacturing the photodetection device according to  claim 3 , wherein the waveguide is directly in lateral contact with the charge layer as well. 
     
     
         5 . The method for manufacturing the photodetection device according to  claim 3 , wherein the waveguide has a line portion and a divergent portion with a narrow end in contact with the line portion and a wide end in contact with the absorption structure and the charge layer. 
     
     
         6 . The method for manufacturing the photodetection device according to  claim 1 , further comprising:
 forming a trench into the semiconductor substrate before formation of the anode, wherein the trench is positioned in a region of the semiconductor substrate to be formed with the anode.   
     
     
         7 . The method for manufacturing the photodetection device according to  claim 6 , further comprising:
 performing an ion implantation process to form a heavily doped region into the anode, wherein the heavily doped region has the second conductive type, and a sidewall of the heavily doped region is shared with the trench.   
     
     
         8 . The method for manufacturing the photodetection device according to  claim 1 , wherein a method for forming the capping material layer comprises:
 forming a passivation layer covering the charge multiplication region and the anode, while exposing the charge layer and the absorption structure; and   performing an epitaxial process to selectively grow a semiconductor material on the exposed charge layer and the exposed absorption structure, for forming the capping material layer.   
     
     
         9 . The method for manufacturing the photodetection device according to  claim 1 , further comprising:
 forming a dielectric layer covering the capping layer, the cathode, the charge multiplication region and the anode; and   forming a first contact plug and a second contact plug through the dielectric layer, wherein the first contact plug is landed on the cathode, and the second contact plug is disposed on the anode.   
     
     
         10 . The method for manufacturing the photodetection device according to  claim 9 , wherein the dielectric layer is spaced apart from the charge layer via the capping layer. 
     
     
         11 . A method for manufacturing a photodetection device, comprising:
 providing a semiconductor substrate with a front semiconductor layer, a back semiconductor layer and a buried insulating layer sandwiched between the front semiconductor layer and the back semiconductor layer;   forming a charge region into the front semiconductor layer, wherein the charge region has a first conductive type;   forming an anode with a second conductive type into the front semiconductor layer, wherein the anode is laterally spaced apart from the charge region, and a portion of the front semiconductor layer in between the charge region and the anode defines a charge multiplication region;   forming a recess into the charge region, such that the charge region is shaped into a charge layer defining the recess;   forming an absorption structure in the recess;   forming a capping material layer covering the absorption structure and the charge layer; and   forming a cathode with the first conductive type into the capping material layer, wherein the cathode is in contact with the absorption structure, and remained portions of the capping material layer define a capping layer entirely covering topmost surfaces of the charge layer.   
     
     
         12 . The method for manufacturing the photodetection device according to  claim 11 , wherein the charge layer, the charge multiplication region and the anode respectively span from a top surface of the front semiconductor layer to a top surface of the buried insulating layer. 
     
     
         13 . The method for manufacturing the photodetection device according to  claim 11 , further comprising:
 patterning the front semiconductor layer to form a waveguide directly in lateral contact with the absorption structure.   
     
     
         14 . The method for manufacturing the photodetection device according to  claim 13 , wherein the waveguide is directly in lateral contact with the charge layer as well. 
     
     
         15 . The method for manufacturing the photodetection device according to  claim 13 , wherein the absorption structure, the charge layer and the anode are each formed in a line shape, and the absorption structure and the charge layer are respectively in lateral contact with the waveguide by one end. 
     
     
         16 . A method for manufacturing a photodetection device, comprising:
 performing an ion implantation process to form a charge region into a semiconductor substrate, wherein the charge region has a first conductive type;   performing an ion implantation process to form anodes with a second conductive type into the semiconductor substrate, wherein the anodes at opposite sides of the charge region are laterally spaced apart from the charge region, and portions of the semiconductor substrate in between the charge region and the anodes respectively define a charge multiplication region;   forming a recess into the charge region, such that the charge region is shaped into a charge layer defining the recess;   forming an absorption structure in the recess;   forming a capping material layer covering the absorption structure and the charge layer; and   performing an ion implantation process to form a cathode with the first conductive type into the capping material layer, wherein the cathode is in contact with the absorption structure, and remained portions of the capping material layer define a capping layer entirely covering topmost surfaces of the charge layer.   
     
     
         17 . The method for manufacturing the photodetection device according to  claim 16 , wherein the charge layer, the charge multiplication regions and the anodes extends into the semiconductor substrate by an identical depth. 
     
     
         18 . The method for manufacturing the photodetection device according to  claim 16 , further comprising:
 patterning the semiconductor substrate to form a waveguide directly in lateral contact with the absorption structure and the charge layer.   
     
     
         19 . The method for manufacturing the photodetection device according to  claim 16 , further comprising:
 forming a dielectric layer covering the capping layer, the cathode, the charge multiplications region and the anodes; and   forming a first contact plug and second contact plugs through the dielectric layer, wherein the first contact plug is landed on the cathode, and the second contact plugs are disposed on the anodes, respectively.   
     
     
         20 . The method for manufacturing the photodetection device according to  claim 19 , wherein the dielectric layer is spaced apart from the charge layer via the capping layer.