Method of manufacturing a varicap diode, a varicap diode, a receiver device, and a TV receiver set
First Claim
1. A method of manufacturing a varicap diode comprising providing a silicon substrate with an epitaxial layer of a first conductivity type with a first zone by providing dopant atoms of a first conductivity type in the epitaxial layer and with a second zone adjoining a surface of the epitaxial layer by providing dopant atoms of a second conductivity type opposed to the first in the epitaxial layer, forming a pn junction between the second zone and the first zone, characterized in that the second zone is provided by providing a layer of polycrystalline silicon having dopant atoms of the second conductivity type on the surface, and diffusing the dopant atoms from this layer into the epitaxial layer to form a pn junction at a distance of less than 0.3 μ
- m from the polycrystalline silicon.
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Accused Products
Abstract
The invention relates to a method of manufacturing a varicap diode whereby a silicon substrate with an epitaxial layer of a first conductivity type is provided with a first zone through the provision of dopant atoms of a first conductivity type in the epitaxial layer and is provided with a second zone adjoining a surface of the epitaxial layer through the provision of dopant atoms of a second conductivity type opposed to the first in the epitaxial layer, a pn junction being formed between the second zone and the first zone. According to the invention, the method is characterized in that the second zone is provided in that a layer of polycrystalline silicon provided with dopant atoms of the second conductivity type is provided on the surface, and in that the dopant atoms are diffused from this layer into the epitaxial layer, whereby a pn junction is formed at a distance of less than 0.3 μm from the polycrystalline silicon. The measure according to the invention leads to the manufacture of a varicap diode with a pn junction which shows a wide variation in capacitance of the depleted region around the pn junction for a comparatively small variation in reverse voltage across the pn junction.
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Citations
6 Claims
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1. A method of manufacturing a varicap diode comprising providing a silicon substrate with an epitaxial layer of a first conductivity type with a first zone by providing dopant atoms of a first conductivity type in the epitaxial layer and with a second zone adjoining a surface of the epitaxial layer by providing dopant atoms of a second conductivity type opposed to the first in the epitaxial layer, forming a pn junction between the second zone and the first zone, characterized in that the second zone is provided by providing a layer of polycrystalline silicon having dopant atoms of the second conductivity type on the surface, and diffusing the dopant atoms from this layer into the epitaxial layer to form a pn junction at a distance of less than 0.3 μ
- m from the polycrystalline silicon.
- View Dependent Claims (2, 3, 4, 5, 6)
Specification