Thursday, December 13, 2007

US 7307030 - Quantum dots formed in substrate concavities

Quantum dot films have been developed with various application in optoelectronics but one problem in forming such films is that the quantum dots are oriented in a random manner making it very difficult to form electronics devices that implement quantum cellular logic or quantum computing. This patent from Fujitsu teaches a method of using oxide to form recesses for quantum dot growth to produce controlled positioning of the quantum dots. Claim 1 reads:

1. A method for forming a quantum dot comprising the steps of: forming an oxide in a dot-shape on a surface of a semiconductor substrate; removing the oxide to form a concavity in a position where the oxide has been removed; and growing a semiconductor layer on the semiconductor substrate with the concavity formed in to form a quantum dot of the semiconductor layer in the concavity.