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US 4,775,643 AGranted
Mesa zener diode and method of manufacture thereof
AssigneeMotorola, Inc.
InventorThomas A. Wetteroth
Life of this patent
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Abstract
A mesa Zener diode is described which is manufactured by ion implanting a region of opposite conductivity into a substrate; etching a moat in a surface of the substrate through the region of opposite conductivity; depositing an oxide layer having an opening exposing a portion of the mesa; and depositing top and bottom metals.
Claims13
A method of manufacturing a Zener diode comprising the steps:
- ion implanting a dopant of a first conductivity type into a surface region of a substrate of a second conductivity type;
- delineating a moat in said substrate such that said moat extends through said surface region, said moat defining a mesa of said substrate;
- oxidizing a first face of said substrate forming an oxide layer thereon, said first face being adjacent said surface region;
- delineating an opening within said oxide layer exposing a portion of said mesa;
- depositing a layer of titanium on said exposed portion of said mesa;
- depositing a layer of nickel of said layer of titanium;
- and
- depositing a layer of silver on said layer of nickel.
5 more elements
A method of manufacturing a Zener diode comprising the steps:
- ion implanting a dopant of a first conductivity type into a surface region of a substrate of a second conductivity type;
- depositing a layer of photoresist on a first face of said substrate, said first face being adjacent said surface region;
- masking said photoresist to define a moat in said photoresist;
- developing said photoresist;
- etching a moat in said substrate, said moat extending through said surface region and said moat defining a mesa of said substrate;
- oxidizing a first face of said substrate forming an oxide layer thereon;
- annealing said Zener diode;
- depositing a second photoresist on said oxide layer;
- masking said second photoresist to define an opening in said photoresist;
- developing said photoresist;
- etching said oxide layer to expose a porton of said mesa;
- depositing a layer of titanium on said exposed portion of said mesa;
- depositing a layer of nickel on said layer of titanium;
- and
- depositing a layer of silver on sai layer of nickel.
12 more elements
Dependencies are inferred from the claim text.