Method of manufacturing semiconductor devices
US5840200A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1997 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Jan 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32136
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A device insulating film, a lower-layer platinum film, a ferroelectric film, an upper-layer platinum film, and a titanium film are sequentially formed on a semiconductor substrate in this order. On the titanium film, a photoresist mask is further formed in a desired pattern. The thickness of the titanium film is adjusted to be 1/10 or more of the total thickness of a multilayer film consisting of the upper-layer platinum film, the ferroelectric film, and the lower-layer platinum film. The titanium film is then subjected to dry etching and the photoresist film is removed by ashing process. The titanium film thus patterned is used as a mask in etching the upper-layer platinum film, the ferroelectric film, and the lower-layer platinum film by a dry-etching method using a plasma of a gas mixture of chlorine and oxygen in which the volume concentration of oxygen gas is adjusted to be 40%. During the dry-etching process, the titanium film is oxidized to provide a high etching selectivity. Subsequently, the titanium film is removed by dry etching using a plasma of chlorine gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.