CMOS Image Sensor and Method for Manufacturing the Same

Abstract

Provided is a CMOS image sensor. The CMOS image sensor can include a semiconductor substrate, a blue photodiode region, a red photodiode region, a green photodiode region, an overcoat layer, and microlenses. The substrate can have a first photodiode region, a second photodiode region, and a transistor region. The blue photodiode region is formed having a predetermined depth in the first photodiode region. The red photodiode region is formed in the first photodiode region having a depth greater than that of the blue photodiode region with a gap separating the red photodiode region from the blue photodiode region. The green photodiode region is formed in the second photodiode region having a depth between the depths of the blue and red photodiode regions. The overcoat layer is formed on the semiconductor substrate, and microlenses are formed on the overcoat layer to correspond to the first and second photodiode regions.

1 . A method for manufacturing a complementary metal oxide semiconductor (CMOS) image sensor, the method comprising:
 preparing a semiconductor substrate having a first photodiode region, a second photodiode region, and a transistor region;   forming a plurality of gate electrodes in the transistor region of the semiconductor substrate;   implanting impurity ions into a portion of the first photodiode region that is located on one side of the gate electrode to form a blue photodiode region having a predetermined depth;   implanting impurity ions into the portion of the first photodiode region in which the blue photodiode region has been formed to form a red photodiode region such that the red photodiode region has a depth deeper than that of the blue photodiode region;   implanting impurity ions into a portion of the second photodiode region to form a green photodiode region such that the green photodiode region has a depth between the depth of the blue photodiode region and the depth of the red photodiode region;   forming source/drain impurity regions in the transistor region at a second side of the gate electrode;   sequentially forming an interlayer insulating layer and an entire surface of the semiconductor substrate; and   forming microlenses on the overcoat layer corresponding to the first photodiode region and the second photodiode region.   
   
   
       2 . The method according to  claim 1 , wherein the blue photodiode region is formed to have a depth of 0.3-0.5 μm. 
   
   
       3 . The method according to  claim 1 , wherein the red photodiode region is formed to have a depth of 4-5 μm. 
   
   
       4 . The method according to  claim 1 , wherein the green photodiode region is formed to have a depth of 1.5-3.0 μm. 
   
   
       5 . The method according to  claim 1 , further comprising forming an impurity region having a conductivity type opposite to that of the blue photodiode region in a surface of the semiconductor substrate in which the blue photodiode region has been formed. 
   
   
       6 . The method according to  claim 5 , wherein the impurity region is formed to have a depth of 0.1 μm or less. 
   
   
       7 . The method according to  claim 1 , wherein the photodiode region is formed 0.5-1.0 μm from a surface of the semiconductor substrate.