CMOS image sensor and method for manufacturing the same
A CMOS image sensor and a method for manufacturing the same are provided, in which a pad opening is formed simultaneously with the formation of a microlens. The CMOS image sensor includes a nitride layer for passivation deposited on an oxide layer, wherein a sacrificial microlens having a microlens structure is formed from a sacrificial microlens layer formed on the nitride layer and wherein, after forming the sacrificial microlens, the nitride layer is transfer-etched to impart the nitride layer with the microlens structure of the sacrificial microlens.
1 . A CMOS image sensor, comprising:
a nitride layer for passivation deposited on an oxide layer,
wherein a sacrificial microlens having a microlens structure is formed from a sacrificial microlens layer formed on said nitride layer and wherein, after forming the sacrificial microlens, said nitride layer is transfer-etched to impart said nitride layer with the microlens structure of the sacrificial microlens.
2 . The CMOS image sensor of claim 1 , further comprising:
a photodiode;
an interlayer dielectric layer formed on the photodiode; and
a first metal layer connected to the photodiode through an electrode, wherein the oxide layer is formed on the first metal layer.
3 . The CMOS image sensor of claim 2 , further comprising:
a first inter-metal dielectric layer;
a second metal layer;
a second inter-metal dielectric layer; and
an upper metal layer, wherein the oxide layer is formed on the upper metal layer.
4 . A method for manufacturing a CMOS image sensor, comprising:
depositing a nitride layer for passivation on an oxide layer;
forming a sacrificial microlens layer on the nitride layer;
forming a sacrificial microlens from the sacrificial microlens layer; and
shaping the second nitride layer as the sacrificial microlens by a transfer etching process.
5 . The method of claim 4 , wherein the nitride layer and the sacrificial microlens are etched at a dry etching ratio of 1:1.
6 . The method of claim 4 , wherein the sacrificial microlens layer is formed only in a pixel array.
7 . The method of claim 4 , further comprising:
forming a photodiode;
depositing an interlayer dielectric layer on the photodiode;
depositing a first metal layer on the interlayer dielectric layer; wherein the oxide layer is formed on the first metal layer.
8 . The method of claim 7 , further comprising:
depositing a first inter-metal dielectric layer on the first metal layer;
depositing a second metal layer on the first inter-metal dielectric layer;
depositing a second inter-metal dielectric layer on the second metal layer; and
depositing an upper metal layer on the second inter-metal dielectric layer, wherein the oxide layer is formed on the upper metal layer.