Method for making a well disposed over a sensor
US10483123B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2018 |
| Grant date | Nov 19, 2019 |
| Priority date | — |
| Expiry date | Apr 4, 2038 |
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.