Method for forming quantum dots
US5229320A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1992 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Jul 28, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/962
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is a method which enabled the precise formation of a group of quantum dots. A device which functions on the principle of a transmission type electron microscope is used to produce a beam of electrons which are passed through a thin crystal membrane in order to produce an electron beam diffraction image. The energy distribution of the diffracted electron beam is used to produce masks, enable epitaxial growth and dry etching involved with the microscopic fabrication operations. For example, a thin GaAs membrane is used to form a diffracted electron beam image on a GaAs layer formed on a substrate. Carbon is then supplied and used to form carbon layers on the the locations where the beam energy is strongest. These carbon layers are used as a mask which allow selective etching of the GaAs layer. An AlGaAs insulating layer is then epitaxially grown on the exposed surface portions of the AlGaAs substrate to fill the spaces between each of the quantum dot defining GaAs portions which project up from the AlGaAs substrate surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.