Keywords silicon germanium, multilayer, heterojunction, bipolar
Start Date: 01-NOV-92 / Duration: 36 months
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The goal of MIDAS is to strengthen the European knowledge base in the area of high-performance silicon microelectronics. The technical objective is to demonstrate the performance enhancement in bipolar transistors by using new materials such as silicon-germanium, new processing techniques such as low-temperature epitaxy, and selected deposition and new device concepts such as heterojunction bipolar transistors. The demonstration of the potential will be done by a combination of performance prediction based on device simulations using data derived from test structures, and the fabrication of bipolar transistors.
Silicon multilayer technology will improve performance characteristics of bipolar devices in terms of speed, noise, linearity and power consumption. It will also create silicon heterojunction devices with additional degrees of freedom with respect to device design and optimisation as compared with homojunction devices. This additional degree of freedom can be used to improve the speed with transit frequencies up to the 100 GHz range, or to improve the analogue features at "moderate" transit frequencies of 20 to 50 GHz.
The technical targets of the project are:
Simulated optimised devices
Fabricated non-optimised devices
Major progress has been made in the growth of structures for bipolar transistors. A range of different technologies, such as MBE, UHV-CVD and APCVD are being used and compared in terms of material quality, growth sequence and time. Aspects of integration of epitaxial growth of Si and SiGe by the different techniques, using selective and non-selective growth, are being investigated.
The first operating transistors have been made in the project. These are meant to either optimise the dopant and/or germanium profiles, or to optimise the device structure for obtain low parasitics. Excellent results in terms of high-frequency performance have been obtained for deposited base transistors. In the modelling area, the missing material parameters, in particular for SiGe, have been identified, and the influence on calculated performance has been evaluated.
Dr A. A. Van Gorkum
NEDERLANDSE PHILIPS BEDRIJVEN BV
Prof. Holstlaan 4
NL - 5656 AA Eindhoven
tel: + 31/ 40 743685
fax: + 31/ 40 743390
NEDERLANDSE PHILIPS BEDRIJVENNL - C
DAIMLER-BENZ AG - D - P
SIEMENS AG - D - P
GEC PLESSEY SEMICONDUCTORS LTD - UK - P
DEFENCE RESEARCH AGENCY - UK - A
MICRO-ELECTRONICA CENTRUM - B - A
LINKOEPING UNIVERSITY - S - A
TELEFUNKEN ELECTRONICD - A
TECHNISCHE UNIVERSITAET WIEN-IAIS - A - A
MIDAS - 6135, December 1993
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html version of synopsis by Nick Cook