Method for manufacturing semiconductor device
US5804034A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1994 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Mar 21, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/712
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for attaining a uniform roughening of a silicon semiconductor surface with a microscopic amount of roughness at the .ANG. level, wherein the amount of roughness may be accurately and precisely controlled without complicating the manufacturing processes and increasing the manufacturing cost, and regardless of the shape of the silicon surface area of the substrate. The substrate with the silicon surface area is immersed in a cleansing solution, such as SC1 for example, containing a metallic substance, such as Fe, Ni, Cu, Zn, Al, and Cr, for example, at the ppb level to wash the surface. Then, a silicon oxide film uniformly containing the metallic substance is formed on the silicon surface of the substrate after drying, and isotropic etching is performed on the surface of the substrate formed with the silicon oxide film by etching Si from the silicon oxide film at a high ratio of selectivity to form microscopic irregularities. This procedure increases the effective surface area of the silicon surface in a highly precise manner and can be employed in making trench type or stack type DRAM memory cell structures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.