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| 2. |
- Hillier, Ladeana W, et al.
(author)
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Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution
- 2004
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In: Nature. - 0028-0836 .- 1476-4687. ; 432:7018, s. 695-716
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Journal article (peer-reviewed)abstract
- We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken is a modern descendant of the dinosaurs and the first non-mammalian amniote to have its genome sequenced, the draft sequence of its genome--composed of approximately one billion base pairs of sequence and an estimated 20,000-23,000 genes--provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes. For example, the evolutionary distance between chicken and human provides high specificity in detecting functional elements, both non-coding and coding. Notably, many conserved non-coding sequences are far from genes and cannot be assigned to defined functional classes. In coding regions the evolutionary dynamics of protein domains and orthologous groups illustrate processes that distinguish the lineages leading to birds and mammals. The distinctive properties of avian microchromosomes, together with the inferred patterns of conserved synteny, provide additional insights into vertebrate chromosome architecture.
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| 3. |
- Erdal, Suvar, et al.
(author)
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High frequency performance of SiGeCHBTs with selectively & non-selectively grown collector
- 2004
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In: Physica Scripta. - 0031-8949 .- 1402-4896. ; T114, s. 138-141
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Journal article (peer-reviewed)abstract
- Two high-frequency heterojunction bipolar transistor (HBT) architectures based on SiGeC have been fabricated and characterized. Different collector designs were applied either by using selective epitaxial growth doped with phosphorous or by non-selective epitaxial growth doped with arsenic. Both designs have a non-selectively deposited SiGeC base doped with boron and a poly-crystalline emitter doped with phosphorous. Both HBT designs exhibit similar electrical characteristics with a peak DC current gain of around 1600 and a BVCEO of 1.8V. The cut-off frequency (f(T)) and maximum frequency of oscillation (f(max)) vary from 40-80 GHz and 15-30 GHz, respectively, depending on lateral design relations. Good high frequency performance for a device with a selectively grown collector is demonstrated for the first time.
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| 4. |
- Grahn, J. V., et al.
(author)
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A low-complexity 62-GHz f(T) SiGe heterojunction bipolar transistor process using differential epitaxy and in situ phosphorus-doped poly-Si emitter at very low thermal budget
- 2000
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In: Solid-State Electronics. - 0038-1101 .- 1879-2405. ; 44:3, s. 549-554
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Journal article (peer-reviewed)abstract
- A low-complexity SiGe heterojunction bipolar transistor process based on differential epitaxy and in situ phosphorus doped polysilicon emitter technology is described. Silane-based chemical vapor deposition at reduced pressure was used for low-temperature SiGe epitaxy. Following SiGe epitaxy, the process temperature budget was kept very low with 900 degrees C for 10 s as the highest temperature step. A very high current gain of almost 2000 and cut off frequency of 62 GHz were achieved for a uniform 12% Ge profile. The breakdown voltage BVCEO and forward Early voltage were equal to 2.9 and 6.5 V, respectively.
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| 5. |
- Haralson, Erik, et al.
(author)
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The effect of C on emitter-base design for a single-polysilicon SiGe : C HBT with an IDP emitter
- 2004
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 224:1-4, s. 330-335
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Journal article (peer-reviewed)abstract
- A differential epitaxy SiGe:C heterojunction bipolar junction transistor (HBT) design is reported and used to study the effect of carbon on junction formation as well as the effect of lateral design parameters on ac and dc performance. The device exhibits a high current gain (beta) of 1700 and a BVCEO of 1.8 V. The peak cutoff frequency (f(T)) and maximum oscillation frequency (f(MAX)) are 73 and 17 GHz, respectively. The effect of emitter overlap on f(T) was minimal, but it had a strong impact on dc performance. LOCOS opening size strongly impacted both ac and dc performance. In addition, the effect of carbon, base cap thickness, and rapid thermal anneal (RTA) temperature on the emitter-base (E-B) junction formation was studied.
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| 6. |
- Hållstedt, Julius, et al.
(author)
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Growth of high quality epitaxial Si1-x-yGexCy layers by using chemical vapor deposition
- 2004
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 224:01-Apr, s. 46-50
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Journal article (peer-reviewed)abstract
- The epitaxial quality of non-selective and selective deposition of Si1-x-yGexCy (0 less than or equal to x less than or equal to 0.30, 0 less than or equal to y less than or equal to 0.02) layers has been optimized by using high-resolution reciprocal lattice mapping (HRRLM). The main goal was to incorporate a high amount of substitutional carbon atoms in Si or Si1-xGex matrix without creating defects. The carbon incorporation behavior was explained by chemical and kinetic effects of the reactant gases during epitaxial process. Although high quality epitaxial Si1-yCy layers can be deposited, lower electron mobility compared to Si layers was observed. (C) 2003 Elsevier B.V. All rights reserved.
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| 7. |
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| 8. |
- Suvar, E., et al.
(author)
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A base-collector architecture for SiGeHBTs using low-temperature CVD epitaxy combined with chemical-mechanical polishing
- 2002
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In: Physica Scripta. - 0031-8949 .- 1402-4896. ; T101, s. 64-66
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Journal article (peer-reviewed)abstract
- A new collector technology intended for an integrated high-speed SiGe heterojunction bipolar transistor (HBT) is reported. The collector was fabricated by selective epitaxial growth (SEG) using chemical vapor deposition at 770degreesC under reduced pressure (20 torr) using SiH2Cl2 as silicon precursor and PH3 as n-type dopant source. Chemical-mechanical polishing (CMP) was applied to the overgrown SEG collector in order to achieve a smooth surface in level with the surrounding oxide. Finally, a SiGe base doped with boron was deposited using non-selective epitaxial growth (NSEG) at 650degreesC. The topography of the collector is inspected after each process step by atomic force microscopy and the topography of the completed collector/base stack indicates that this structure is promising for fabrication of the emitter window. A further advantage with the CMP procedure is the elimination of phosphorous segregation as evidenced by secondary ion mass spectroscopy of the base-collector stack.
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| 9. |
- Suvar, Erdal, et al.
(author)
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Characterization of leakage current related to a selectively grown collector in SiGeC heterojunction bipolar transistor structure
- 2004
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 224:1-4, s. 336-340
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Journal article (peer-reviewed)abstract
- Sources of base-collector and base-emitter leakage current in a SiGeC-based heterojunction bipolar transistor (HBT) with a selectively grown and chemical-mechanical polished (CMP) collector are discussed. Transmission electron microscopy and electrical measurement have been applied to investigate the leakage current. It has been demonstrated that the edge-located defects generated by selective epitaxy process are the origin of the junction leakage.
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