Comlase Ab

Surface Technology Systems Plc

Anand Srinivasan

N Peter Blixt

Svante H S&ouml;derholm

Carl-Fredrik Carlstr&ouml;m

Carl-Fredrik Carlstrom

Christofer Silvenius

L Karsten V Lindstr&ouml;m

Svante Soderholm

Lauerant Krummenacher

L Karsten V Lindstrom

Lauerent Krummenacher

Gunnar Landgren

A substrate whose elemental constituents are selected from Groups III and V of the Periodic Table, is provided with pre-defined masked regions. Etching of the substrate comprising the steps of: a) forming a gas containing molecules having at least one methyl group (CH) linked to nitrogen into a plasma; and b) etching the unmasked regions of the substrate by means of the plasma. For a substrate whose elemental constituents are selected from Groups II and VI of the Periodic Table, the plasma etching gas used is trimethylamine. Since the methyl compound of nitrogen has a lower bond energy than for hydrocarbon mixtures, free methyl radicals are easier to obtain and the gas is more efficient as a methyl source. In addition, compared with hydrocarbon mixtures, reduced polymer formation can be expected due to preferential formation of methyl radicals over polymer-generating hydrocarbon radicals because of the lower bond energy for the former.

Plasma etching

A method to obtain contamination free surfaces of a material chosen from the group comprising GaAs, GaAlAs, InGaAs, InGaAsP and InGaAs at crystal mirror facets for GaAs based laser cavities. The crystal mirrors facets are cleaved out exposed to an ambient atmosphere containing a material from the group comprising air, dry air, or dry nitrogen ambients. Any oxides and other foreign contaminants obtained during the ambient atmosphere exposure of the mirror facets are removed by dry etching in vacuum. Thereafter, a native nitride layer is grown on the mirror facets by treating them with nitrogen.

Method to obtain contamination free laser mirrors and passivation of these

The invention relates to a method using dry etching to obtain contamination free surfaces on of a material chosen from the group comprising GaAs, GaAlAs, InGaAsP, and InGaAs to obtain nitride layers on arbitrary structures on GaAs based lasers, and a GaAs based laser manufactured in accordance with the method. The laser surface is provided with a mask masking away parts of its surface to be prevented from dry etching. The laser is then placed in vacuum. Dry etching is then performed using a substance chosen from the group containing: chemically reactive gases, inert gases, a mixture between chemically reactive gases and inert gases. A native nitride layer is created using plasma containing nitrogen. A protective layer and/or a mirror coating is added.

Method to GaAs based lasers and a GaAs based laser

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Huddinge, Sweden

Anand Srinivasan