Photodetector array having different photodiode structures

US8754495B1 · kind B1 · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Hiroyuki Tomomatsu · Tokyo, JP
• Motoaki Kusamaki · Beppu, JP
• Kohichi Kubota · Beppu, JP
• Yuta Masuda · Hiroshima, JP
• Akihiro Sugihara · Beppu, JP
• Hiroshi Kitada · Tuckahoe, US
• Takeshi Konno · Tokyo, JP

Key dates

• Filing date: Apr 26, 2013
• Grant date: Jun 17, 2014
• Expiry date: Apr 26, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/18

Abstract

A method of fabricating a photodiode array having different photodiode structures includes providing a semiconductor substrate having first and second diode areas including a bottom substrate portion doped with a first doping type, an intrinsic layer, and a top silicon layer doped with a second doping type. The second diode areas are implanted with the second doping type. A dopant concentration in the surface of the second diode areas is at least three times higher than in the first diode areas. The top silicon layer is thermally oxidized to form a thermal silicon oxide layer to provide a bottom Anti-Reflective Coating (ARC) layer. The second diode areas grow thermal silicon oxide thicker as compared to the first diode areas. A top ARC layer is deposited on the bottom ARC layer. First PDs are provided in the first diode areas and second PDs provided in the second diode areas.