Back side illumination image sensor and manufacturing method thereof
View Patent ↗A manufacturing method of a BSI image sensor includes providing a substrate having a plurality of photo-sensing elements and a plurality of multilevel interconnects formed on a first side of the substrate; forming a redistribution layer (RDL) and a first insulating layer covering the RDL on the front side of the substrate; providing a carrier wafer formed on the front side of the substrate; forming a color filter array (CFA) on a second side of the substrate, the second side being opposite to the first side; removing the carrier wafer; and forming a first opening in the first insulating layer for exposing the RDL.
1. A manufacturing method of a back side illumination (BSI) image sensor, comprising:
providing a substrate having a plurality of photo-sensing elements and a plurality of multilevel interconnects formed on a first side of the substrate;
forming a bonding pad and a first insulating layer covering the bonding pad on the first side of the substrate;
forming a redistribution layer (RDL) and a second insulating layer covering the RDL on the first insulating layer, the RDL being electrically connected to the bonding pad;
providing a carrier wafer formed on the first side of the substrate after forming the RDL and the second insulating layer;
performing a wafer thinning process to a second side of the substrate after providing the carrier wafer, the second side being opposite to the first side;
forming a color filter array (CFA) on the second side of the substrate after performing the wafer thinning process;
removing the carrier wafer; and
forming a second opening in the second insulating layer on the first side of the substrate for exposing the RDL after removing the carrier wafer.
2. The manufacturing method of a BSI image sensor according to claim 1 , further comprising forming a first opening in the first insulating layer for exposing the bonding pad before forming the RDL.
3. The manufacturing method of a BSI image sensor according to claim 2 , wherein the RDL electrically connected to the bonding pad through the first opening.
4. The manufacturing method of a BSI image sensor according to claim 2 , wherein the first opening and the second opening are spaced apart from each other.
5. The manufacturing method of a BSI image sensor according to claim 1 , further comprising performing a planarization process to the second insulating layer before providing the carrier wafer.
6. The manufacturing method of a BSI image sensor according to claim 1 , wherein the substrate comprises a reduced thickness after the step of thinning the substrate, and the reduced thickness is between 1.8 micrometer (μm) and 3 μm.
7. The manufacturing method of a BSI image sensor according to claim 1 , further comprising forming a protecting member on the CFA.
8. The manufacturing method of a BSI image sensor according to claim 1 , further comprising forming a conductive structure electrically connected to the RDL in the second opening.