N-type ohmic electrode for n-type group III nitride semiconductor, semiconductor light-emitting device with the electrode, and method for forming n-type ohmic electrode
AssigneeShowa Denko K.K.
InventorTakashi Udagawa
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Abstract
The present invention provides a constitution of n-type ohmic electrode suitable for n-type group III nitride semiconductor, and a forming method thereof for providing low contact resistivity. The n-type ohmic electrode is provided to comprise an alloy of aluminum and lanthanum or comprises lanthanum at the junction interface with the n-type group III nitride semiconductor. The method comprising forming a lanthanum-aluminum alloy layer at 300° C. or less to form an n-type ohmic electrode enriched in lanthanum at the junction interface.
Claims9
An n-type ohmic electrode for use with an n-type Group III nitride semiconductor, which is provided to contact with the surface of an n-type Group III nitride semiconductor layer, wherein the n-type ohmic electrode layer is made of an alloy of aluminum (atomic symbol:
- Al) and lanthanum (atomic symbol:
- La) or comprises lanthanum, and wherein the lanthanum content in the n-type ohmic electrode layer is 10 mass % or more on the surface contacting with the n-type Group III nitride semiconductor layer.
A semiconductor light-emitting device fabricated by providing an ohmic contact electrode on a stacked structure body in which an n-type Group III nitride semiconductor layer and a p-type compound semiconductor layer are provided on one surface of a crystalline substrate and a light-emitting layer is interposed between the n-type and p-type compound semiconductor layers, wherein the n-type ohmic electrode provided to contact with the n-type Group III nitride semiconductor layer is made of a lanthanum-aluminum alloy layer or a lanthanum layer, the n-type ohmic electrode comprises a lanthanum-aluminum alloy layer has a lanthanum content of 10 mass % or more at the junction interface with the n-type Group III nitride semiconductor layer and has a lanthanum content of less than 10 mass % in the region 30 nm or more distant from the junction interface.
A method for forming an n-type ohmic electrode for use with an n-type Group III nitride semiconductor, which is provided to contact with the surface of an n-type Group III nitride semiconductor layer, wherein the n-type ohmic electrode layer is made of an alloy of aluminum (atomic symbol:
- Al) and lanthanum (atomic symbol:
- La) or comprises lanthanum, and wherein the lanthanum content in the n-type ohmic electrode layer is 10 mass % or more on the surface contacting with the n-type Group III nitride semiconductor layer, which method comprises forming a lanthanum-aluminum alloy layer constituting the n-type ohmic electrode, by using a lanthanum-dialuminum alloy (compositional formula:
- LaAl2) as a raw material.
A method for producing a semiconductor light-emitting device fabricated by providing an ohmic contact electrode on a stacked structure body in which an n-type Group III nitride semiconductor layer and a p-type compound semiconductor layer are provided on one surface of a crystalline substrate and a light-emitting layer is interposed between the n-type and p-type compound semiconductor layers, wherein the n-type ohmic electrode provided to contact with the n-type Group III nitride semiconductor layer is made of a lanthanum-aluminum alloy layer or a lanthanum layer, the n-type ohmic electrode comprises a lanthanum-aluminum alloy layer has a lanthanum content of 10 mass % or more at the junction interface with the n-type Group III nitride semiconductor layer and has a lanthanum content of less than 10 mass % in the region 30 nm or more distant from the junction interface, which method comprises providing an ohmic contact electrode on a stacked structure body in which an n-type Group III nitride semiconductor layer and a p-type compound semiconductor layer are provided on one surface of a crystalline substrate and a light-emitting layer is interposed between the n-type and p-type compound semiconductor layers, wherein the lanthanum-aluminum alloy layer constituting an n-type ohmic electrode which contacts with the n-type Group III nitride semiconductor layer is formed by using a lanthanum-dialuminum alloy (compositional formula:
- LaAl2) as a raw material.
Dependencies are inferred from the claim text.