Image sensor and method of manufacturing the same

A method of manufacturing an image sensor, the method comprising:

• forming a metal line and an interlayer insulation layer on a semiconductor substrate including a readout circuit;
• forming an image detection unit with stacked first and second doping layers on the interlayer insulation layer;
• forming a pixel separation unit that penetrates the image detection unit to separate the image detection unit by each pixel;
• forming a via hole that penetrates the image detection unit and the interlayer insulation layer, the first via hole being in a region adjacent to the pixel separation unit and exposing the metal line;
• forming a first barrier pattern at a sidewall of the via hole to cover the second doping layer and expose the first doping layer;
• forming a first metal contact in the via hole, the first metal contact being electrically connected to the metal line;
• forming a second barrier pattern on the first metal contact in the via hole;
• forming a trench on the second barrier pattern to expose the second doping layer;
• and
• forming a second metal contact in the trench to be electrically connected to the second doping layer.

An image sensor comprising:

• a semiconductor substrate including a readout circuit formed for each pixel;
• an interlayer insulation layer and first metal lines electrically connected to respective readout circuits on the semiconductor substrate, wherein the first metal lines comprise a first metal line for a first pixel and a first′ metal line for a second pixel adjacent the first pixel, the first metal line and the first′ metal line being adjacent a boundary region between the first pixel and the second pixel;
• an image detection unit on the interlayer insulation layer and including stacked first and second doping layers;
• a pixel separation unit penetrating the image detection unit to separate the image detection unit according to each pixel;
• a first metal contact for the first pixel and a first′ metal contact for the second pixel penetrating the image detection unit and the interlayer insulation layer at sides of the pixel separation unit, the first metal contact and the first′ metal contact being electrically connected to the first and first′ metal lines, respectively;
• a first barrier pattern at an upper sidewall of each of the first and first′ metal contacts to isolate the first and first′ metal contacts from the second doping layer while exposing the first and first′ metal contacts to the first doping layer;
• a second barrier pattern for the first pixel and a second′ barrier pattern for the second pixel on the first and first′ metal contacts, respectively;
• and
• a second metal contact formed in a trench above the first and first′ metal contacts to be electrically connected to the second doping layer of the image detection units that are separated into at least the first pixel and the second pixel by the pixel separation unit, while being isolated from the first and first′ metal contacts by the second and second′ barrier patterns.

A method of manufacturing an image sensor, the method comprising:

• forming a readout circuit for each pixel on a semiconductor substrate;
• forming an interlayer insulation layer on the semiconductor substrate, the interlayer insulation layer including adjacent first and first′ metal lines electrically connected to respective readout circuits;
• forming an image detection unit on the interlayer insulation, the image detection unit including stacked first and second doping layers;
• forming a pixel separation unit that penetrates the image detection unit to separate the image detection unit by each pixel;
• forming first and first′ via holes penetrating the image detection unit and the interlayer insulation layer at opposite sides of the pixel separation unit, the first and first′ via holes exposing the first and first′ metal lines, respectively;
• forming a first barrier pattern at sidewalls of the first and first′ via holes to cover the second doping layer and expose the first doping layer;
• forming first and first′ metal contacts in the first and first′ via holes, the first and first′ metal contacts being electrically connected to the first and first′ metal lines, respectively;
• forming second and second′ barrier patterns respectively on the first and first′ metal contacts in the first and first′ via holes;
• forming a trench on the second barrier pattern, the pixel separation unit, and the second′ barrier pattern to selectively expose the second doping layer of the image detection unit at both sides of the pixel separation unit;
• and
• forming a second metal contact in the trench to be electrically connected to the second doping layer of the image detection units that are separated into at least two by the pixel separation unit.