United Microelectronics Corp.

Feng-Ming Liu

Chen-Bin Lin

Chong-Yao Chen

Yu-Ju Liu

James Ho

A structure of a CMOS image sensory device is described. A photodiode sensory region and a transistor device region are isolated from each other by an isolation layer formed in the substrate. A gate structure is located on the transistor device region, and a source/drain region is in the transistor device region beside the side of the gate structure. A doped region is in the photodiode sensory region. A self-aligned block is located on the photodiode sensory region and a protective layer is formed on the entire substrate.

Structure of a CMOS image sensor

A fabrication method for a CMOS image sensory device is described. An isolation layer is formed in the substrate to isolate a photodiode sensory region and a transistor device region. A gate structure is further formed on the transistor device region, followed by forming concurrently a source/drain region in the transistor device region beside the side of the gate structure and a doped region in the photodiode sensory region. Thereafter, a self-aligned block is formed on the photodiode sensory region, followed by forming a protective layer on the substrate.

Method for fabricating a CMOS image sensor

A plurality of active pixel sensors are formed on the surface of a semiconductor wafer. The semiconductor wafer comprises a P-type substrate, an active pixel sensor region and a periphery circuit region. A first active pixel sensor block mask (APSB mask) is formed to cover the active pixel sensor region, then at least one N-well on the surface of the semiconductor wafer not covered by the first APSB mask is formed. A second APSB mask and at least one N-well mask are formed to cover the active pixel sensor region and the region outside the P-well region. At least one P-well on the surface of the semiconductor wafer not covered by the second APSB mask and the N-well mask is formed. Finally, at least one photodiode and at least one complementary metal-oxide semiconductor (CMOS) transistor are formed on the surface of the active pixel sensor region.

Method for making an active pixel sensor

The present invention is a method for integrating an anti-reflection layer and a salicide block. The method comprises the following steps: A substrate is provided that is divided into at least a sensor area and a transistor area, wherein the sensor area comprises a doped region and the transistor area comprises a transistor that includes a gate, a source and a drain; forming a composite layer on the substrate, wherein the composite layer at least also covers both the sensor area and the transistor area, and the composite layer increases the refractive index of light that propagates from the doped region into the composite layer; performing an etching process and a photolithography process to remove part of the composite layer and to let top of the gate, the source and the drain are not covered by the composite layer; and performing a salicide process to let top of the gate, the source and the drain are covered by a silicate. One main characteristic of the invention is that the composite layer can be used as an anti-reflection layer of the sensor area and a salicide block of the transistor region. The composite layer is made of several basic layers and refractive index of any basic layer is different from refractive indexes of adjacent basic layers.

Method for integrating anti-reflection layer and salicide block

The present invention is a method for integrating an anti-reflection layer and a salicide block. The method comprises following steps: provide a substrate that is divided into at least a sensor area and a transistor area, wherein the sensor area comprises a doped region and the transistor area comprises a transistor that includes a gate, a source and a drain; forms a composite layer on the substrate, herein the composite layer at least also covers both sensor area and transistor area, and the composite layer increases refractive index of light that propagate from the doped region into the composite layer; performs an etching process and a photolithography process to remove part of the composite layer and to let top of the gate, the source and the drain are not covered by the composite layer; and performs a salicide process to let top of the gate, the source and the drain are covered by a silicate. One main characteristic of the invention is that the composite layer can be used as an anti-reflection layer of the sensor area and a salicide block of the transistor region. The composite layer is made of several basic layers and refractive index of any basic layer is different to refractive indexes of adjacent basic layers.

A process for fabricating a mixed signal integrated circuit on a substrate, wherein the substrate is partially covered with a field oxide layer. An oxide layer is formed over a portion of the substrate, wherein the portion of the substrate is not covered with the field oxide layer. First impurities are implanted into the substrate, wherein the first impurities damage the oxide layer. A buffer layer is formed over the oxide layer. A polysilicon layer is formed over the buffer layer. Second impurities are implanted into the polysilicon layer, wherein the buffer layer prevents the oxide layer form being damaged by the second impurities. The polysilicon layer is etched to remove the polysilicon layer, wherein the buffer layer prevents the oxide layer and the substrate from being etched. The portion of buffer layer and the damaged oxide layer over the substrate are removed. The gate oxide layer is formed over the substrate.

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Fengshan, Taiwan

Feng-Ming Liu