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US5834800A Expired / Lapsed US ⏱️ 0.0 years remaining

Heterojunction bipolar transistor having mono crystalline SiGe intrinsic base and polycrystalline SiGe and Si extrinsic base regions

Assignee: Bell Semiconductor LLC
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Filing: 1996-03-04
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Granted: 1998-11-10
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Expires: 2016-03-04
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Abstract

Abstract A heterojunction bipolar transistor in an integrated circuit has intrinsic and extrinsic base portions. The intrinsic base portion substantially comprises epitaxial silicon-germanium alloy. The extrinsic base portion substantially comprises polycrystalline material, and contains a distribution of ion-implanted impurities. An emitter overlies the intrinsic base portion, and a spacer at least partially overlies the emitter. The spacer overhangs the extrinsic base portion by at least a distance characteristic of lateral straggle of the ion-implanted impurities.

Inventors

  • 👤 Bahram Jalali-Farahani
  • 👤 Clifford Alan King

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 00:14
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/021; H10D10/80; H10D10/821; H10D10/891

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 148 words
An integrated electronic device comprising a heterojunction bipolar transistor, said transistor comprising a collector, base, and emitter of respective first, second, and first conductivity types, wherein: (a) the base comprises an intrinsic base and an extrinsic base; (b) the emitter and collector substantially comprise single-crystalline silicon; (c) the intrinsic base is included between the emitter and collector and substantially comprises epitaxial silicon-germanium alloy; (d) the extrinsic base laterally adjoins the intrinsic base and the emitter, and substantially comprises polycrystalline silicon and polycrystalline silicon-germanium alloy; (e) the extrinsic base comprises ion-implanted impurities of the second conductivity type; (f) the emitter is partially overlain by a dielectric spacer that partially overhangs the extrinsic base by an overhang length at least equal to a distance of lateral straggle characteristic of the ion-implanted impurities; and (g) said overhang length is at least about 150 nm, and not more than about 400 nm.
Claim 2
Dependent Claim 148 words
An integrated electronic device comprising a heterojunction bipolar transistor, said transistor comprising a collector, base, and emitter of respective first, second, and first conductivity types, wherein: (a) the base comprises an intrinsic base and an extrinsic base; (b) the emitter and collector substantially comprise single-crystalline silicon; (c) the intrinsic base is included between the emitter and collector and substantially comprises epitaxial silicon-germanium alloy; (d) the extrinsic base laterally adjoins the intrinsic base and the emitter, and substantially comprises polycrystalline silicon and polycrystalline silicon-germanium alloy; (e) the extrinsic base comprises ion-implanted impurities of the second conductivity type; (f) the emitter is partially overlain by a dielectric spacer that partially overhangs the extrinsic base by an overhang length at least equal to a distance of lateral straggle characteristic of the ion-implanted impurities; and (g) said overhang length is at least about 150 nm, and not more than about 400 nm.
Claim 3
Dependent Claim 186 words
An integrated electronic device comprising a heterojunction bipolar transistor, said transistor comprising a collector, base, and emitter of respective first, second, and first conductivity types, wherein: (a) the base comprises an intrinsic base and an extrinsic base; (b) the emitter and collector substantially comprise single-crystalline silicon; (c) the intrinsic base is included between the emitter and collector and substantially comprises epitaxial silicon-germanium alloy; (d) the extrinsic base laterally adjoins the intrinsic base and the emitter, and substantially comprises polycrystalline silicon and polycrystalline silicon-germanium alloy; (e) the extrinsic base comprises ion-implanted impurities of the second conductivity type; (f) the emitter is partially overlain by a dielectric spacer that partially overhangs the extrinsic base by an overhang length at least equal to a distance of lateral straggle characteristic of the ion-implanted impurities; (g) there is a p-n junction between the extrinsic base and the emitter, and there is an interface between polycrystalline silicon and single-crystalline silicon approximately where the extrinsic base adjoins the emitter; and (h) said junction lies on the single-crystalline side of said interface at a distance of about 500 Å or less from said interface.
Claim 4
Dependent Claim 186 words
An integrated electronic device comprising a heterojunction bipolar transistor, said transistor comprising a collector, base, and emitter of respective first, second, and first conductivity types, wherein: (a) the base comprises an intrinsic base and an extrinsic base; (b) the emitter and collector substantially comprise single-crystalline silicon; (c) the intrinsic base is included between the emitter and collector and substantially comprises epitaxial silicon-germanium alloy; (d) the extrinsic base laterally adjoins the intrinsic base and the emitter, and substantially comprises polycrystalline silicon and polycrystalline silicon-germanium alloy; (e) the extrinsic base comprises ion-implanted impurities of the second conductivity type; (f) the emitter is partially overlain by a dielectric spacer that partially overhangs the extrinsic base by an overhang length at least equal to a distance of lateral straggle characteristic of the ion-implanted impurities; (g) there is a p-n junction between the extrinsic base and the emitter, and there is an interface between polycrystalline silicon and single-crystalline silicon approximately where the extrinsic base adjoins the emitter; and (h) said junction lies on the single-crystalline side of said interface at a distance of about 500 Å or less from said interface.
Claim 5
Dependent Claim 186 words
An integrated electronic device comprising a heterojunction bipolar transistor, said transistor comprising a collector, base, and emitter of respective first, second, and first conductivity types, wherein: (a) the base comprises an intrinsic base and an extrinsic base; (b) the emitter and collector substantially comprise single-crystalline silicon; (c) the intrinsic base is included between the emitter and collector and substantially comprises epitaxial silicon-germanium alloy; (d) the extrinsic base laterally adjoins the intrinsic base and the emitter, and substantially comprises polycrystalline silicon and polycrystalline silicon-germanium alloy; (e) the extrinsic base comprises ion-implanted impurities of the second conductivity type; (f) the emitter is partially overlain by a dielectric spacer that partially overhangs the extrinsic base by an overhang length at least equal to a distance of lateral straggle characteristic of the ion-implanted impurities; (g) there is a p-n junction between the extrinsic base and the emitter, and there is an interface between polycrystalline silicon and single-crystalline silicon approximately where the extrinsic base adjoins the emitter; and (h) said junction lies on the single-crystalline side of said interface at a distance of about 200 Å or less from said interface.
Claim 6
Dependent Claim 186 words
An integrated electronic device comprising a heterojunction bipolar transistor, said transistor comprising a collector, base, and emitter of respective first, second, and first conductivity types, wherein: (a) the base comprises an intrinsic base and an extrinsic base; (b) the emitter and collector substantially comprise single-crystalline silicon; (c) the intrinsic base is included between the emitter and collector and substantially comprises epitaxial silicon-germanium alloy; (d) the extrinsic base laterally adjoins the intrinsic base and the emitter, and substantially comprises polycrystalline silicon and polycrystalline silicon-germanium alloy; (e) the extrinsic base comprises ion-implanted impurities of the second conductivity type; (f) the emitter is partially overlain by a dielectric spacer that partially overhangs the extrinsic base by an overhang length at least equal to a distance of lateral straggle characteristic of the ion-implanted impurities; (g) there is a p-n junction between the extrinsic base and the emitter, and there is an interface between polycrystalline silicon and single-crystalline silicon approximately where the extrinsic base adjoins the emitter; and (h) said junction lies on the single-crystalline side of said interface at a distance of about 200 Å or less from said interface.

References Cited (Backward Citations)

US5250448A Cited
US5106767A Cited
US5365090A Cited
US5525825A Cited
US5620907A Cited

USPTO Annuity & Maintenance Windows

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