Method of manufacturing charge storage device
US7405166B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2006 |
| Grant date | Jul 29, 2008 |
| Priority date | — |
| Expiry date | Jan 25, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/033
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of manufacturing a charge storage device is provided. Utilizing the capacity for a precise control of the thickness and the silicon content of a deposited film in an atomic layer deposition process, a stacked gradual material layer such as a hafnium silicon oxide (HfxSiyOz) layer is formed. The silicon content is gradually changed throughout the duration of the HfxSiyOz deposition process. The etching rate for the HfxSiyOz layer in dilute hydrogen fluoride solution is dependent on the silicon content y in the HfxSiyOz layer. The sidewalls of the stacked gradual material layer are etched to form an uneven profile. The lower electrode, the capacitor dielectric layer and the upper electrode are formed on the uneven sidewalls of the stacked gradual material layers, the area between the lower electrode and the upper electrode is increased to improve the capacitance of the charge storage device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.