Successful Preparation of High Frequency HBT by Integrated RTCVD Processes

AbstractComplete epitaxial Si-SiGe-Si- stacks with a defined doping profile for each component have been deposited on Si substrates from the system SiH4, GeH4, H2, B2H6, PH3 by RTCVD. The deposition has been carried out at a temperature of 650°C for Si and of 500°C for SiGe, respectively, both at a pressure of 2 mbar. The developed epitaxial process including an effective H2 in-situ preclean annealing has been integrated in a simple double mesa technology for the preparation of SiGe base heterojunction bipolar transistors (HBT). Despite the simplicity of the technology and the lithographical level allowing emitter dimensions of 2.3×2.5 μm2 only, test devices on 4” wafers reached transit frequencies fT and maximum oscillation frequencies fmax of higher than 60 GHz and 30 GHz, respectively. Besides, a low base current has been measýnl as proof for a good layer quality.

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High Speed GaAs Based Devices on Si Substrates

MRS Proceedings ◽

10.1557/proc-67-149 ◽

1986 ◽

Vol 67 ◽

Cited By ~ 1

Author(s):

Hadis Morkoc

Keyword(s):

Heterojunction Bipolar Transistors ◽

High Speed ◽

Bipolar Transistors ◽

Annealing Process ◽

Current Gain ◽

Device Performance ◽

Microwave Frequencies ◽

Si Substrates ◽

Cutoff Frequencies ◽

Oscillation Frequencies

ABSTRACTRemarkably good device performance at both dc and microwave frequencies has recently been obtained from GaAs based devices grown on Si substrates. In GaAs MESFETs on Si, current gain cutoff frequencies and maximum oscillation frequencies of fT = 13.3 GHz and fmax = 30 GHz have been obtained for 1.2μm devices, which is nearly identical to the performance achieved in GaAs on GaAs technology for both direct implant and epitaxial technology. For heterojunction bipolar transistors, current gain cutoff frequencies and maximum oscillation frequencies of fT = 30 GHz and fmax = 11.3 GHz have been obtained for emitter dimensions of 4×20μm2. In GaAs AlGaAs MODFETs. current gain cut-off frequencies of about 15 GHz with lμm gates were obtained on GaAs and Si substrates. The pseudomorphic InGaAs/GaAs MODFETs were also fabricated and found to be comparable to GaAs MODFETs although they should perform better. The structures were also shown to maintain their properties when put through ion implantation and annealing process. Given the performance already demonstrated in GaAs on Si devices and the advantages afforded by this technology, the growth of III-Vs on Si promises to play an important role in the future of heterojunction electronics.

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High-frequency output characteristics of AlGaAs/GaAs heterojunction bipolar transistors

Electronics Letters ◽

10.1049/el:19901328 ◽

1990 ◽

Vol 26 (25) ◽

pp. 2058 ◽

Cited By ~ 4

Author(s):

J. Chen ◽

G.B. Gao ◽

M.S. Ünlü ◽

H. Morkoç

Keyword(s):

Heterojunction Bipolar Transistors ◽

High Frequency ◽

Bipolar Transistors ◽

Frequency Output ◽

Output Characteristics

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SiGe Heteroepitaxy for High Frequency Circuits

MRS Proceedings ◽

10.1557/proc-525-379 ◽

1998 ◽

Vol 525 ◽

Cited By ~ 3

Author(s):

B. Tillack ◽

D. Bolze ◽

G. Fischer ◽

G. Kissinger ◽

D. Knoll ◽

...

Keyword(s):

Heterojunction Bipolar Transistors ◽

High Frequency ◽

Defect Density ◽

Process Capability ◽

Chemical Vapor ◽

Bipolar Transistors ◽

Capability Indices ◽

Data Points ◽

B Doping ◽

The Stability

ABSTRACTWe have determined the process capability of Low Pressure (Rapid Thermal) Chemical Vapor Deposition (LP(RT)CVD) of epitaxial Si/SiGe/Si stacks for heterojunction bipolar transistors (HIBTs). The transistor parameters primarily influenced by the epitaxial characteristics were measured for 600 identically processed 4” wafers. The results demonstrate that it is possible to control accurately the epitaxial process for a 25 nm thick graded SiGe base profile with 20 % Ge and very narrow B doping (5 nm). The pipe limited device yield of about 90 % for an emitter area of 104 μm2 indicates a very low defect density in the epitaxial layer stack. The process capability indices determined from about 40,000 data points demonstrate the stability and capability of the LP(RT)CVD epitaxy with regard to manufacturing requirements.

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