Dopant Implantation Hardmask for Forming Doped Isolation Regions in Image Sensors

• Main Authors: TAI HSINIH, CHEN GANG, RHODES HOWARD, QIAN YIN, YANG RONGSHENG, VENEZIA VINCENT, MAO DULI, KU KEHIANG
• Format: Patent
• Language: English
• Published: 20.12.2012
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Forming a doped isolation region in a substrate during manufacture of an image sensor. A method of an aspect includes forming a hardmask layer over the substrate, and forming a photoresist layer over the hardmask layer. An opening is formed in the photoresist layer over an intended location of the doped isolation region. An opening is etched in the hardmask layer by exposing the hardmask layer to one or more etchants through the opening. The opening in the hardmask layer may have a width of less than 0.4 micrometers. The doped isolation region may be formed in the substrate beneath the opening in the hardmask layer by performing a dopant implantation that introduces dopant through the opening in the hardmask layer. The method of an aspect may include forming sidewall spacers on sidewalls of the opening in the hardmask layer and using the sidewall spacers as a dopant implantation mask.