Method for forming dielectric film of capacitor having different thicknesses partly
US6207487A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1999 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Oct 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/0228
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention discloses a method for forming a dielectric film having improved leakage current characteristics in a capacitor. A lower electrode having a surface and a rounded protruding portion is formed on a semiconductor substrate. The surface and the protruding portion define at least one concave area. A chemisorption layer is then formed on the surface and the rounded protruding portion by supplying a first reactant. Also, a physisorption layer is formed on the chemisorption layer from the first reactant. Next, a portion of the physisorption layer is removed and a portion of the physisorption layer is left on the concave area. Subsequently, the chemisorption layer and the portion of the physisorption layer on the concave area react with a second reactant to form a dielectric film on the surface of the lower electrode. The thickness of said dielectric film is greater on the concave area than on the protruding portion, thereby reducing leakage current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.