Optical Sensor with Light-Guiding Feature and Method for Preparing the Same

Abstract

An optical sensor includes a semiconductive layer having an electrical circuit area and an optical sensing area, a sample-holding portion over the optical sensing area, a light-guiding structure between the sample-holding portion and the optical sensing area, and an electrical interconnect structure over the electrical circuit area. The electrical interconnect structure is integrally formed with the light-guiding structure, and the light-guiding structure is configured to direct an emitting light from the sample-holding portion to the optical sensing area.

What is claimed is: 
     
         1 . An optical sensor, comprising:
 a semiconductive layer comprising an electrical circuit area and an optical sensing area;   a sample-holding portion over the optical sensing area;   a light-guiding structure between the sample-holding portion and the optical sensing area; and   an electrical interconnect structure over the electrical circuit area;   wherein the electrical interconnect structure is integrally formed with the light-guiding structure, and the light-guiding structure is configured to direct an emitting light from the sample-holding portion to the optical sensing area.   
     
     
         2 . The optical sensor of  claim 1 , wherein the electrical interconnect structure comprises at least one electrical contact over the electrical circuit area, and the light-guiding structure comprises at least one first light-guiding part over the optical sensing area. 
     
     
         3 . The optical sensor of  claim 2 , wherein the semiconductive layer has a horizontal upper surface, and the at least one electrical contact and the at least one first light-guiding part extend substantially in a same horizontal plane, which is in parallel to and above the horizontal upper surface. 
     
     
         4 . The optical sensor of  claim 2 , wherein the light-guiding structure comprises a plurality of first light-guiding parts arranged in a ring. 
     
     
         5 . The optical sensor of  claim 2 , wherein the at least one first light-guiding part is a ring-shaped part. 
     
     
         6 . The optical sensor of  claim 2 , wherein the electrical interconnect structure comprises at least one electrical via over the at least one electrical contact, and the light-guiding structure comprises at least one second light-guiding part over the at least one first light-guiding part. 
     
     
         7 . The optical sensor of  claim 6 , wherein the semiconductive layer has a horizontal upper surface, and the at least one electrical via and the at least one second light-guiding part extend substantially in a same horizontal plane, which is in parallel to and above the horizontal upper surface. 
     
     
         8 . The optical sensor of  claim 6 , wherein the light-guiding structure comprises a plurality of second light-guiding parts arranged in a ring. 
     
     
         9 . The optical sensor of  claim 6 , wherein the at least one second light-guiding part is a ring-shaped part. 
     
     
         10 . The optical sensor of  claim 1 , wherein the light-guiding structure extends from a horizontal upper surface of the semiconductive layer. 
     
     
         11 . The optical sensor of  claim 1 , wherein the light-guiding structure comprises an inner light-guiding bar in a first layer over the semiconductive layer and an outer light-guiding bar in a second layer over the semiconductive layer. 
     
     
         12 . The optical sensor of  claim 1 , wherein a width of the light-guiding structure is larger in an upper region close to the sample-holding portion than that in a bottom region close to the light-sensing region. 
     
     
         13 . The optical sensor of  claim 1 , wherein a width of the light-guiding structure is larger in a bottom region close to the light-sensing region than that in the upper region close to the sample-holding portion. 
     
     
         14 . An optical sensor, comprising:
 a semiconductive layer comprising an electrical circuit area and an optical sensing area;   a sample-holding portion over the optical sensing area;   at least one electrical contact over the electrical circuit area; and   at least one first light-guiding part configured to direct an emitting light from the sample-holding portion to the optical sensing area;   wherein the semiconductive layer has a horizontal upper surface, the at least one first light-guiding part is between the sample-holding portion and the optical sensing area, and the at least one electrical contact and the at least one first light-guiding part extend substantially in a same horizontal plane, which is in parallel to and above the horizontal upper surface.   
     
     
         15 . The optical sensor of  claim 14 , wherein the at least one electrical contact is integrally formed with the at least one first light-guiding part. 
     
     
         16 . An optical sensor, comprising:
 a semiconductive layer comprising an optical sensing area;   a sample-holding portion over the optical sensing area; and   a light-guiding structure configured to direct an emitting light from the sample-holding portion to the optical sensing area;   wherein the light-guiding structure comprises at least one light-guiding spacer extending from a horizontal upper surface of the semiconductive layer, and the light-guiding structure has a tapering top end near the sample-holding portion.   
     
     
         17 . The optical sensor of  claim 16 , wherein the light-guiding structure comprises a plurality of light-guiding spacers arranged in a ring. 
     
     
         18 . The optical sensor of  claim 16 , wherein the light-guiding structure comprises a ring-shaped guiding part. 
     
     
         19 . The optical sensor of  claim 16 , comprising a plurality of dielectric layers over the optical sensing area, wherein the at least one light-guiding spacer extends through the plurality of dielectric layers. 
     
     
         20 . The optical sensor of  claim 16 , wherein the light-guiding structure has a sidewall tilted with respect to the semiconductive layer, and an included angle between the horizontal upper surface of the semiconductive layer and the sidewall is about 60 degrees to 89.5 degrees.