Method of fabricating an image sensor
AssigneeUnited Microelectronics Corp.
InventorsTze-Jing Chen, Ching-Chung Chen, Tung-Hu Lin, Chen-Bin Lin, Chi-Rong Lin
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Abstract
A method of fabricating an image sensor on a semiconductor substrate including a sensor array region is introduced. First, an R/G/B color filter array (CFA) is formed on portions of the semiconductor substrate corresponding to the sensor array region. Then, a spacer layer is formed on the R/G/B CFA, and a plurality of U-lens is formed on the spacer layer corresponding to the R/G/B CFA. Afterwards, a buffer layer is coated to fill a space between the U-lens, and a low-temperature passivation layer is deposited on the buffer layer and the U-lens at a temperature of about 300° C. or less to prevent the R/G/B CFA from damage.
Claims15
A method of fabricating an image sensor on a semiconductor substrate comprising a sensor array region, the method comprising:
- forming a planarizing layer on the semiconductor substrate;
- forming an R/G/B color filter array (CFA) on a portion of the planarizing layer corresponding to the sensor array region;
- forming a spacer layer on the R/G/B CFA;
- forming a plurality of U-lenses on the spacer layer above the R/G/B CFA with a space positioned between each adjacent U-lens;
- coating the image sensor with a buffer layer to fill the space between adjacent U-lens;
- depositing a passivation layer on the buffer layer and the U-lenses;
- and
- forming a bonding pad opening over the semiconductor substrate outside the sensor array region.
A method of fabricating an image sensor of a CMOS, the method comprising:
- providing a semiconductor substrate comprising a photoelectric conversion region with a plurality of photodiodes and a plurality of insulators positioned between the photodiodes;
- forming a first planarizing layer;
- forming a patterned metal layer on the semiconductor substrate corresponding to the respective insulator and outside the photoelectric conversion region;
- forming a second planarizing layer on the semiconductor substrate;
- forming an R/G/B color filter array (CFA) on the second planarizing layer corresponding to the respective photodiode;
- forming a spacer layer on the R/G/B CFA;
- forming a plurality of U-lenses on the spacer layer corresponding to the respective R/G/B CFA with a space positioned between each adjacent U-lens;
- coating with a buffer layer to fill the space between each adjacent U-lens, the buffer layer having a predetermined index of refraction (IR) to adjust a focus plane generated from incident light passing through the U-lens;
- depositing a passivation layer on the buffer layer and the U-lens;
- and
- forming a bonding pad on the semiconductor substrate outside the photoelectric conversion region by the following steps:
- forming a patterned photoresist layer on the passivation layer outside the photoelectric conversion region to define a pattern of the bonding pad;
- and
- performing an etching process to form an opening connecting the patterned metal layer.
Dependencies are inferred from the claim text.