Atomic layer etching of iii-v materials
AssigneeCommissariat à I'Énergie Atomique et aux Énergies Alternatives
InventorStéphane Cadot
Life of this patent
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Abstract
A method of ALE etching of a III-V material including the following steps: a) placing in an enclosure a structure including a layer of III-V material, b) implementing, in the enclosure, at an etching temperature, one or more times the following ALE cycle: oxidizing a surface of the layer of III-V material with an oxidizing gas, whereby an oxide layer is formed, purging the enclosure with an inert gas flow, exposing the formed oxide layer to thionyl chloride vapor to etch the oxide layer, and purging the enclosure with an inert gas flow.
Claims8
Method of ALE etching of a III-V material comprising the following steps:
- a) placing in an enclosure a structure comprising a substrate covered by a layer of III-V material,
- b) implementing, in the enclosure, at an etching temperature, one or more times the following atomic layer etching cycle:
- oxidizing a surface of the layer of III-V material with an oxidizing gas, whereby an oxide layer is formed,
- purging the enclosure with an inert gas flow,
- exposing the formed oxide layer to thionyl chloride vapor to etch the oxide layer,
- purging the enclosure with an inert gas flow,
- c) preferably, depositing a layer of interest on the surface of the etched layer of III-V material.
Method of manufacturing a power device, for example a transistor, preferably an HEMT-type transistor, comprising a substrate covered by a GaN layer and one or more additional layers of III-V material selected from among AlGaN and AlN, holes extending through the additional layer and opening into the GaN layer, the through holes having been formed by a reactive ion etching step,
- the method comprising the following steps:
- a) placing the device in an enclosure,
- b) implementing, in the enclosure at an etching temperature preferably in the range from 200° C. to 600° C., one or more times the following cycle of ALE steps to perform a post-etching cleaning:
- exposing the device to an oxidizing gas, whereby an oxide layer is formed on a surface of the GaN layer exposed to the oxidizing gas, where a surface of the additional layer may also be oxidized,
- purging the enclosure with an inert gas flow,
- exposing the device to thionyl chloride vapor to selectively etch the oxide layer of the GaN layer,
- purging the enclosure with an inert gas flow,
- c) depositing in the through holes a layer of interest, in particular a metal layer, for example made of TiN, or a layer of dichalcogenide, for example made of VS2, the layer of interest being in contact with the etched surface of the GaN layer,
- step c) being carried out in the enclosure used during step b).
Method of manufacturing an optoelectronic device, for example a micro-LED, comprising a substrate covered by a stack comprising an n-doped GaN layer, quantum wells, for example made of InGaN/GaN, a p-doped GaN layer, and a layer of transparent conductive oxide, the stack having been etched by reactive ion etching, in order to form pixels, the n-doped GaN layer being partially etched,
- the method comprising the following steps:
- a) placing the device in an enclosure,
- b) implementing, in the enclosure at an etching temperature preferably in the range from 200° C. to 600° C., one or more times the following cycle of ALE steps to perform a post-etching cleaning:
- exposing the device to an oxidizing gas, whereby a surface of the stack exposed to the oxidizing gas is oxidized and an oxide layer is formed,
- purging the enclosure with an inert gas flow,
- exposing the device to thionyl chloride vapor to etch the oxide layer,
- purging the enclosure with an inert gas flow,
- c) depositing between the pixels and on the sides of the pixels a dielectric layer, for example made of SiO2, Al2O3, SiN, or AlN, step c) being carried out in the enclosure used during step b).
Dependencies are inferred from the claim text.