FeRAM sidewall diffusion barrier etch
US6713342B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 29, 2002 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Nov 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/696
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to a method of forming an FeRAM integrated circuit, which includes forming a sidewall diffusion barrier prior to etching the bottom electrode diffusion barrier layer. The sidewall diffusion barrier layer is then etched prior to the bottom electrode diffusion barrier layer. In patterning an AlOx sidewall diffusion barrier layer prior to etching the underlying bottom electrode diffusion barrier layer, the etch chemistry comprises BCl3+Ar. The BCl3 is effective in etching the AlOx with a good selectivity to the underlying nitride hard mask on top of the capacitor stack (e.g., TiAlN) and nitride bottom electrode diffusion barrier (e.g., TiAlON with small oxygen content) between the neighboring capacitor stacks. The Ar may be added to the etch chemistry because the resulting surface (of a top portion of the hard mask and the bottom electrode diffusion barrier) is smoother.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.