CMOS image sensor and method for fabricating the same
View Patent ↗A Complementary Metal Oxide Semiconductor (CMOS) image sensor and methods for fabricating the same. In one example embodiment of the invention, a method for manufacturing a Complementary Metal Oxide Semiconductor (CMOS) image sensor includes several acts. First, a metal pad is formed over a semiconductor substrate. Next, a protection film is formed over the semiconductor substrate and the metal pad. Then, the protection film is selectively removed to expose a surface of the metal pad. Next, a first planarization film is formed over the protection film. Then, a color filter layer is formed over the first planarization film. Next, a second planarization layer is formed over the color filter layer. Then, a first material layer is formed over the second planarization layer. Next, a second material layer is formed over the first material layer. Then, a micro lens is formed out of the first and second material layers.
1. A method for manufacturing a Complementary Metal Oxide Semiconductor (CMOS) image sensor, the method comprising:
forming a metal pad over a semiconductor substrate;
forming a protection film over the semiconductor substrate and the metal pad;
selectively removing the protection film to expose a surface of the metal pad;
forming a first planarization film over the protection film;
forming a color filter layer over the first planarization film;
forming a second planarization layer over the color filter layer;
forming a first material layer over the second planarization layer;
forming a second material layer over the first material layer; and
forming a micro lens out of the first and second material layers,
wherein the first material layer comprises a Deep UltraViolet (DUV) photoresist material layer, and
the second material layer comprises a Middle UltraViolet (MUV) photoresist material layer.
2. The method of claim 1 , wherein the first and second material layers are simultaneously developed.
3. The method of claim 1 , wherein forming a metal pad over a semiconductor substrate comprises forming an aluminum metal pad over a semiconductor substrate.
4. The method of claim 1 , wherein forming a protection film over the semiconductor substrate and the metal pad comprises forming an oxide protection film over the semiconductor substrate and the metal pad.
5. The method of claim 1 , wherein forming a protection film over the semiconductor substrate and the metal pad comprises forming a nitride protection film over the semiconductor substrate and the metal pad.
6. The method of claim 1 , wherein forming a first material layer over the second planarization layer comprises forming a first material layer having a thickness between about 0.1 μm to about 1.0 μm over the second planarization layer.
7. The method of claim 1 , further comprising performing an oxygen plasma treatment over a whole surface of the semiconductor substrate 200 using plasma having oxygen between about 1 sccm and about 26 sccm, a buffer argon (Ar) gas between about 105 sccm and about 195 sccm, a pressure between about 70 mT and about 130 mT, and a power between about 105 W and about 195 W.
8. The method of claim 1 , wherein forming a micro lens out of the first and second material layers further comprises forming first, second and third micro lenses out of the first and second material layers such that a gap between the first and second micro lenses is about 50 nm or less and a gap between the second and third micro lenses is about 50 nm or less.
9. A method for manufacturing a Complementary Metal Oxide Semiconductor (CMOS) image sensor, the method comprising:
forming a metal pad over a semiconductor substrate;
forming a protection film over the semiconductor substrate and the metal pad;
selectively removing the protection film to expose a surface of the metal pad;
forming a first planarization film over the protection film;
forming a color filter layer over the first planarization film;
forming a second planarization layer over the color filter layer;
forming a first material layer over the second planarization layer;
forming a second material layer over the first material layer; and
forming a micro lens out of the first and second material layers,
wherein the first material layer comprises a Deep UltraViolet (DUV) photoresist material layer and the second material layer comprises a Middle UltraViolet (MUV) photoresist material layer, and
wherein a Critical Dimension (CD) of the MUV photoresist material layer is greater than a CD of the DUV photoresist material layer.
10. A method for manufacturing a Complementary Metal Oxide Semiconductor (CMOS) image sensor, the method comprising:
forming a metal pad over a semiconductor substrate;
forming a protection film over the semiconductor substrate and the metal pad; selectively removing the protection film to expose a surface of the metal pad;
forming a first planarization film over the protection film;
forming a color filter layer over the first planarization film;
forming a second planarization layer over the color filter layer;
forming a first material layer over the second planarization layer;
forming a second material layer over the first material layer; and
forming a micro lens out of the first and second material layers,
wherein forming a micro lens out of the first and second material layers comprises:
patterning the second material layer by exposure and development in a photolithography process using a mask;
patterning the first material layer by exposure and development in a photolithography process using the same mask;
performing a bleach process on the first material layer; and
forming a substantially hemispherical shaped micro lens out of the first and second material layers by applying a thermal energy to the first and second material layers at a temperature between about 150° C. to about 300° C.