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US 10,707,323 B2Granted
Method of forming metal contacts in the barrier layer of a group III-N HEMT
AssigneeTexas Instruments Incorporated
InventorsYoshikazu Kondo, Shoji Wada, Hiroshi Yamasaki, Masahiro Iwamoto
Life of this patent
Estimating the term…
Abstract
Metal contact openings are etched in the barrier layer of a group III-N HEMT with a first gas combination that etches down into the barrier layer, and a second gas combination that etches further down into the barrier layer to a depth that lies above the top surface of a channel layer that touches and lies below the barrier layer.
Claims16
A method of forming a high electron mobility transistor comprising:
- forming a buffer layer over a substrate;
- forming a channel layer over the buffer layer;
- forming an AlGaN layer over the channel layer;
- forming a cap layer over the AlGaN layer;
- forming a layer of SiN over the cap layer;
- forming a source contact and a drain contact through the layer of SiN, the cap layer, and into the layer of AlGaN, wherein a bottom surface of the source contact and a bottom surface of the drain contact are within the AlGaN layer and are spaced apart from the channel layer, wherein forming the source contact and the drain contact comprises:
- etching the layer of SiN, cap layer, and AlGaN layer with a first gas combination that includes a chlorine source and a fluorine source to form a source contact opening and a drain contact opening;
- etching the AlGaN layer with a second gas combination that includes two chlorine sources to deepen the source contact opening and the drain contact opening;
- depositing a metal contact layer in the source contact opening and the drain contact opening;
- and
- planarizing the metal contact layer to form the source contact and the drain contact.
8 more elements
A method of forming a high electron mobility transistor comprising:
- forming a buffer layer over a substrate;
- forming a channel layer over the buffer layer;
- forming an AlGaN layer over the channel layer;
- forming a cap layer over the AlGaN layer;
- forming a layer of SiN over the cap layer;
- forming a source contact and a drain contact through the layer of SiN, the cap layer, and into the layer of AlGaN, wherein a bottom surface of the source contact and a bottom surface of the drain contact are within the AlGaN layer and are spaced apart from the channel layer, wherein forming the source contact and the drain contact comprises:
- etching the layer of SiN, cap layer, and AlGaN layer with a gas combination that includes boron trichloride (BCl3) and sulfur hexafluoride (SF6) to form a source contact opening and a drain contact opening;
- etching the AlGaN layer with a second gas combination that includes boron trichloride (BCl3) and chlorine (Cl2) to deepen the source contact opening and the drain contact opening;
- depositing a metal contact layer in the source contact opening and the drain contact opening;
- and
- planarizing the metal contact layer to form the source contact and the drain contact.
8 more elements
A method of forming a high electron mobility transistor comprising:
- forming a buffer layer over a substrate;
- forming a channel layer over the buffer layer;
- forming an AlGaN layer over the channel layer;
- forming a cap layer over the AlGaN layer;
- forming a layer of SiN over the cap layer;
- forming a source contact and a drain contact through the layer of SiN, the cap layer, and into the layer of AlGaN by:
- etching the layer of SiN, cap layer, and AlGaN layer with a first gas combination to form a source contact opening and a drain contact opening;
- etching the AlGaN layer with a second gas combination, different than the first gas combination, to deepen the source contact opening and the drain contact opening;
- depositing a metal contact layer in the source contact opening and the drain contact opening;
- and
- planarizing the metal contact layer to form the source contact and the drain contact, wherein a bottom surface of the source contact and a bottom surface of the drain contact are within the AlGaN layer and are spaced apart from the channel layer.
8 more elements
Dependencies are inferred from the claim text.