TWI456743B - Method for fabricating image sensor - Google Patents

Claims (20)

A method for manufacturing an image sensor, comprising: providing a substrate of the image sensor; forming a plurality of photoresist patterns arranged in a first array on the substrate, wherein a top view of each of the photoresist patterns is substantially Forming a square; and performing a heat flow step such that the photoresist patterns become a plurality of microlenses, the microlenses are arranged in a second array, and the curvature is gradually reduced from the center to the edge of the second array. The method of manufacturing an image sensor according to claim 1, wherein the photoresist patterns have substantially the same area, but the height is gradually decreased from the center to the edge of the first array. The method for manufacturing an image sensor according to claim 2, wherein the photoresist patterns are defined by a plurality of mask patterns, the mask patterns are arranged in a third array, and the light transmittance is From the center to the edge of the third array is gradually increased. The method of manufacturing an image sensor according to claim 3, wherein each of the mask patterns comprises a light transmitting portion and an opaque portion, and a ratio of the light transmitting portion to a mask pattern area is determined by the third array. The center is gradually increasing toward the edge. The method of manufacturing an image sensor according to claim 4, wherein the light transmitting portion comprises a plurality of strip-shaped light transmitting regions. The method of manufacturing an image sensor according to claim 4, wherein the light transmitting portion comprises a plurality of dot-shaped light transmitting regions. The method of manufacturing an image sensor according to claim 1, wherein the image sensor is a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor. A method for manufacturing an image sensor includes: providing a substrate of the image sensor; forming a plurality of photoresist patterns arranged in a first array on the substrate, wherein any two adjacent photoresist patterns are connected or close to each other And performing a heat flow step such that the photoresist patterns become a plurality of microlenses, wherein any two adjacent microlenses are connected, and each of the microlenses has substantially the same curvature in a longitudinal section in each direction, and the microlens rows In a second array, the curvature is tapered from the center to the edge of the second array. The method for manufacturing an image sensor according to claim 8, wherein the photoresist patterns are defined by a plurality of mask patterns, the mask patterns are arranged in a third array, and each light is The mask pattern has a light transmittance distribution in which the light transmittance is gradually increased from the center of itself to the edge of itself. The method of manufacturing an image sensor according to claim 9, wherein each of the mask patterns comprises a plurality of light-transmitting scattering rings in a concentric shape. The method of manufacturing an image sensor according to claim 10, wherein the light transmittance distribution of each of the mask patterns is adjusted by at least one of the number and the width of the light-scattering rings. The method of manufacturing an image sensor according to claim 10, wherein a width of the light-scattering ring of the reticle pattern is gradually decreased from a center to an edge of the third array. The method of manufacturing an image sensor according to claim 10, wherein a spacing of adjacent light-scattering rings of the reticle patterns is increased from a center-to-edge of the third array. The method of manufacturing an image sensor according to claim 8, wherein the image sensor is a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor. A method for manufacturing an image sensor, comprising: providing a substrate of the image sensor; forming a plurality of photoresist patterns arranged in a first array on the substrate, wherein each of the photoresist patterns comprises diagonally arranged Two first sub-patterns and two second sub-patterns arranged diagonally, the first sub-patterns being formed by a first lithography process, and the second sub-patterns being formed by a second lithography process, the first The sub-pattern overlaps with the second sub-patterns, and the shape of each of the first sub-patterns is different from each of the second sub-patterns; and a heat flow step is performed to make the photoresist patterns into a plurality of micro-lenses, The microlenses are arranged in a second array, and the focal length is gradually increased from the center to the edge of the second array. The method for manufacturing an image sensor according to claim 15, wherein a center pitch of the first sub-pattern of the two photoresist patterns and a center pitch of the second sub-pattern are fixed, and the photoresists are fixed. The area of the first or second sub-pattern in the pattern is increased from the center to the edge of the first array. The method for manufacturing an image sensor according to claim 16, wherein a top view of each of the first sub-patterns is substantially circular, and a top view of each of the second sub-patterns is substantially octagonal. The octagon corresponds to a square in which the four corners are truncated. The method of manufacturing an image sensor according to claim 17, wherein a radius of the first sub-pattern of the photoresist patterns is gradually increased from a center to an edge of the first array. The method of manufacturing an image sensor according to claim 17, wherein the area of the square of the second sub-pattern corresponding to the second sub-pattern is truncated by the center to the edge of the first array. . The method of manufacturing an image sensor according to claim 15, wherein the image sensor is a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor.