Method of patterning polyamic acid layers
US6221567A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1999 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Jan 8, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02071
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods of etching polyamic acid layers and the like are disclosed. In exemplary embodiments of the present invention, the polymeric acid layer to be etched is alternatively exposed to etchant solutions (etchants) and rinse solutions, where the etchant solutions are of relatively moderate alkalinity and the rinse solutions have a lower pH than the etchant solutions. The present invention enables polymeric acid layers to be developed with standard basic etchants at relatively moderate concentrations and at room temperature with little, if any, corrosion to any underlying metal layers. The present invention enables the more reliable and cleaner spin-spray processing method to be employed, thereby significantly increasing yields and reducing overall processing costs. The present invention also enables the etching of thick layers of polymeric acid without the need for special treatments, such as exposure to highly concentrated etchant solutions or high temperature processing conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.