Patent · US Active

Method for making a well disposed over a sensor

US11004690B2 · kind B2 · utility

0Cited by
1References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 18, 2019
Grant dateMay 11, 2021
Priority date—
Expiry dateNov 18, 2039

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L21/32133
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method for forming a well providing access to a sensor pad includes patterning a first photoresist layer over a dielectric structure disposed over the sensor pad; etching a first access into the dielectric structure and over the sensor pad, the first access having a first characteristic diameter; patterning a second photoresist layer over the dielectric structure; and etching a second access over the dielectric structure and over the sensor pad. The second access has a second characteristic diameter. The first and second accesses overlapping. A diameter ratio of the first characteristic diameter to the second characteristic diameter is not greater than 0.7. The first access exposes the sensor pad. The second access has a bottom depth less than a bottom depth of the first access.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.