Bipolar transistor having a particular contact structure
First Claim
1. A bipolar transistor comprising:
- a semiconductor substrate of a first conductivity type having a main surface;
a collector region of a second conductivity type formed at the main surface of said semiconductor substrate;
a base region of the first conductivity type formed at a surface of said collector region;
an emitter region of the second conductivity type formed at a surface of said base region;
an insulating layer formed on the main surface of said semiconductor substrate, and having first, second and third openings reaching portions of the surface of said collector region, a surface of the emitter region and the surface of said base region, respectively; and
a collector electrode formed in said first opening and a base electrode and a emitter electrode electrically connected to said base region through said third opening, said emitter region through said second opening, respectively whereina concentration of impurity of the second conductivity type contained in said collector region located immediately under said base region is 5×
1018 cm-3 or less, andL representing a length in a longitudinal direction of the portion of the surface of said emitter region in said second opening and S representing a width of the portion of the surface of the emitter region in said second opening in a direction perpendicular to said longitudinal direction satisfy a relationship that a value of L/S is about 9.3 or more, wherein the collector region does not comprise a high concentration buried diffusion layer of the second conductivity type.
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Accused Products
Abstract
A base region and an emitter region are formed at a surface of an n-well region (collector region). A contact hole reaching a portion of the surface of the collector region is formed, a contact hole reaching a portion of the surface of the emitter region is formed, and a contact hole reaching a portion of the surface of the base region is formed. A collector electrode, an emitter electrode and a base electrode are formed in the contact holes, respectively. Assuming that L represents a longitudinal length of the contact hole accommodating the emitter electrode and S represents a width thereof perpendicular to the longitudinal direction, a value of L/S is 10 or more. Thereby, a collector resistance of a bipolar transistor can be reduced, and a manufacturing cost can be reduced.
13 Citations
20 Claims
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1. A bipolar transistor comprising:
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a semiconductor substrate of a first conductivity type having a main surface; a collector region of a second conductivity type formed at the main surface of said semiconductor substrate; a base region of the first conductivity type formed at a surface of said collector region; an emitter region of the second conductivity type formed at a surface of said base region; an insulating layer formed on the main surface of said semiconductor substrate, and having first, second and third openings reaching portions of the surface of said collector region, a surface of the emitter region and the surface of said base region, respectively; and a collector electrode formed in said first opening and a base electrode and a emitter electrode electrically connected to said base region through said third opening, said emitter region through said second opening, respectively wherein a concentration of impurity of the second conductivity type contained in said collector region located immediately under said base region is 5×
1018 cm-3 or less, andL representing a length in a longitudinal direction of the portion of the surface of said emitter region in said second opening and S representing a width of the portion of the surface of the emitter region in said second opening in a direction perpendicular to said longitudinal direction satisfy a relationship that a value of L/S is about 9.3 or more, wherein the collector region does not comprise a high concentration buried diffusion layer of the second conductivity type. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A bipolar transistor comprising:
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a semiconductor substrate of a first conductivity type having a main surface; a collector region of a second conductivity type formed at the main surface of said semiconductor substrate; a base region of the first conductivity formed at a surface of said collector region; first and second emitter regions of the second conductivity type formed at a surface of said base region with a space from each other; an insulating layer formed on the main surface of said semiconductor substrate, and having a first opening reaching a portion of the surface of said base region, second and third openings spaced from each other with said first opening therebetween and reaching portions of surfaces of said first and second emitter regions, respectively, and fourth and fifth openings spaced from each other with said second and third openings therebetween and reaching portions of the surface of said collector region; a base electrode electrically connected to said base region through said first opening; first and second emitter electrodes electrically connected to said first emitter region through said second opening, said second emitter region through said third opening, respectively; and first and second collector electrodes formed in said fourth and fifth openings, respectively;
whereina concentration of impurity of the second conductivity type contained in said collector region located immediately under said base region is 5×
1018 cm-3 or less, andL1 and S1 representing a length in a longitudinal direction of the portion of the surface of said first emitter region in said second opening and a width of the portion of the surface of said first emitter region in said second opening in a direction perpendicular to said longitudinal direction, respectively, and L2 and S2 representing a length in a longitudinal direction of the portion of the surface of said second emitter region in said third opening and a width of the portion of the surface of said second emitter region in said third opening in a direction perpendicular to said longitudinal direction, respectively, satisfy a relationship that (L1/S1)+(L2/S2) is 9.3 or more. - View Dependent Claims (9, 10, 11, 18)
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12. A bipolar transistor comprising:
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a semiconductor substrate of a first conductivity type having a main surface; a collector region of a second conductivity type formed at the main surface of said semiconductor substrate; first and second base regions of the first conductivity type formed at a surface of said collector region; first and second emitter regions of the second conductivity type formed at surfaces of said first and second base regions, respectively; an insulating layer formed on the main surface of said semiconductor substrate, and having a first opening reaching a portion of the surface of said collector region, second and third openings spaced from each other with said first opening therebetween and reaching portions of surfaces of said first and second emitter regions, respectively, and fourth and fifth openings spaced from each other with said second and third openings therebetween and reaching portions of the surfaces of said first and second base regions, respectively; a collector electrode formed in said first opening; first and second emitter electrodes electrically connected to said first emitter region through said second opening, said second emitter region through said third opening, respectively; and first and second base electrodes electrically connected to said first base region through said fourth opening, said second base region through said fifth opening, respectively;
whereina concentration of impurity of the second conductivity type contained in said collector region located immediately under said base region is 5×
1018 cm-3 or less, andL1 and S1 representing a length in a longitudinal direction of the portion of the surface of said first emitter region in said second opening and a width of the portion of the surface of said first emitter region in said second opening in a direction perpendicular to said longitudinal direction, respectively, and L2 and S2 representing a length in a longitudinal direction of the portion of the surface of said second emitter region in said third opening and a width of the portion of the surface of said second emitter region in said third opening in a direction perpendicular to said longitudinal direction, respectively, satisfy a relationship that (L1/S1)+(L2/S2) is 9.3 or more. - View Dependent Claims (13, 14, 15)
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16. A semiconductor device having a bipolar transistor, and comprising:
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a semiconductor substrate of a first conductivity type having a main surface; a well region of a second conductivity type formed at the main surface of said semiconductor substrate; an MOS transistor formed on the surface of said well region, and having source/drain regions of the first conductivity type; a collector region spaced from said well region and formed at the main surface of said semiconductor substrate; a base region of the first conductivity type formed at a surface of said collector region; an emitter region of the second conductivity type formed at a surface of said base region; an insulating layer formed on the main surface of said semiconductor substrate, and having first, second and third openings reaching portions of the surface of said collector region, a surface of the emitter region and the surface of the base region, respectively; and a collector electrode formed in said first opening and a base electrode and a emitter electrode electrically connected to said base region through said third opening, said emitter region through said second opening, respectively, wherein a concentration of impurity of the second conductivity type contained in said collector region located immediately under said base region is substantially equal to a concentration of impurity of the second conductivity type contained in said well region, and L representing a length in a longitudinal direction of the portion of the surface of said emitter region in said second opening and S representing a width of the portion of the surface of said emitter region in said second opening in a direction perpendicular to said longitudinal direction satisfy a relationship that a value of L/S is about 9.3 or more, wherein the collector region does not comprise a high concentration buried diffusion layer of the second conductivity type. - View Dependent Claims (17, 19, 20)
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Specification