Multi-layer mask including non-photodefinable laser energy absorbing layer for substrate dicing by laser and plasma etch
US9620379B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2014 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Mar 11, 2034 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/56
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods of dicing substrates having a plurality of ICs. A method includes forming a multi-layered mask comprising a laser energy absorbing, non-photodefinable topcoat disposed over a water-soluble base layer disposed over the semiconductor substrate. Because the laser light absorbing material layer is non-photodefinable, material costs associated with conventional photo resist formulations may be avoided. The mask is direct-write patterned with a laser scribing process to provide a patterned mask with gaps. The patterning exposes regions of the substrate between the ICs. Absorption of the mask layer within the laser emission band (e.g., UV band and/or green band) promotes good scribe line quality. The substrate may then be plasma etched through the gaps in the patterned mask to singulate the IC with the mask protecting the ICs during the plasma etch. The soluble base layer of the mask may then be dissolved subsequent to singulation, facilitating removal of the layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.