Alkaline pretreatment for electroplating
US9435049B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 2013 |
| Grant date | Sep 6, 2016 |
| Priority date | — |
| Expiry date | Jan 17, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D3/38
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Prior to electrodeposition, a semiconductor wafer having one or more recessed features, such as through silicon vias (TSVs), is pretreated by contacting the wafer with a pre-wetting liquid comprising a buffer (such as a borate buffer) and having a pH of between about 7 and about 13. This pre-treatment is particularly useful for wafers having acid-sensitive nickel-containing seed layers, such as NiB and NiP. The pre-wetting liquid is preferably degassed prior to contact with the wafer substrate. The pretreatment is preferably performed under subatmospheric pressure to prevent bubble formation within the recessed features. After the wafer is pretreated, a metal, such as copper, is electrodeposited from an acidic electroplating solution to fill the recessed features on the wafer. The described pretreatment minimizes corrosion of seed layer during electroplating and reduces plating defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.