Method for forming doped epitaxial layer of contact image sensor

US11508859B2 · kind B2 · utility

Assignee

• Shanghai Huali Microelectronics Corporation · CN

Inventors

• Chenchen Qiu · Shanghai, CN
• Jun Qian · Sunnyvale, US
• Chang Sun · Singapore, SG
• Zhengying Wei · Shanghai, CN

Key dates

• Filing date: Jan 6, 2021
• Grant date: Nov 22, 2022
• Expiry date: Aug 15, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/184

Abstract

The disclosure discloses a method for forming a doped epitaxial layer of contact image sensor. Epitaxial growth is performed in times. After each time of epitaxial growth, trench isolation and ion implantation are performed to form deep and shallow trench isolation running through a large-thickness doped epitaxial layer. Through cyclic operation of epitaxial growth, trench isolation and ion implantation, the photoresist and hard mask required at each time do not need to be too thick. In the process of trench isolation and ion implantation, the photoresist and etching morphologies are good, such that the lag problem of the prepared contact image sensor is improved. By forming the large-thickness doped epitaxial layer by adopting the method for forming the doped epitaxial layer of the contact image sensor, a high-performance contact image sensor applicable to high quantum efficiency, small pixel size and near infrared/infrared can be prepared.