Active solid-state devices (e.g. – transistors – solid-state diode – Bipolar transistor structure – With enlarged emitter area
Patent
1997-05-16
1998-07-28
Saadat, Mahshid D.
Active solid-state devices (e.g., transistors, solid-state diode
Bipolar transistor structure
With enlarged emitter area
257579, 257584, 257592, H01L 27082, H01L 27102, H01L 2970, H01L 3111
Patent
active
057866228
ABSTRACT:
A novel ring shaped emitter structure with an extrinsic base and base contact in the central portion of the ring is described. This structural configuration is useful for improving the performance of bipolar transistors used in BiCMOS integrated circuits with only minimal changes to conventional CMOS processing technology. A single additional mask is required to form the intrinsic base region of the transistor. The emitter is diffused from a polysilicon layer which also serves as the emitter contact. The polysilicon layer overlies a perimeter portion of an active region defined by an opening in a field oxide and rises up over the field oxide itself. The active emitter region then forms a ring along the perimeter of the active region. The extrinsic base is formed through an opening within the polysilicon layer representing a central portion of the active region. This configuration improves transistor performance by reducing the characteristic spacings and thereby reducing component resistances and capacitances and increasing the cut-off frequency. The improved emitter-base design thereby results in higher bipolar transistor performance in BiCMOS integrated circuits at minimal cost.
REFERENCES:
patent: 4151542 (1979-04-01), Yajima et al.
patent: 4868135 (1989-09-01), Ogura et al.
patent: 4951108 (1990-08-01), Leduc
patent: 5352924 (1994-10-01), Mahant-Shetti et al.
patent: 5409845 (1995-04-01), Robinson et al.
patent: 5523614 (1996-06-01), Hashimoto
patent: 5541433 (1996-07-01), Lien
patent: 5572063 (1996-11-01), Iranmanesh
S. Wolf. "Silicon Processing for the VLSI Era-vol. 2" Lattice Press, Sunset Beach, CA, 1990, pp. 531 & 586.
Ackerman Stephen B.
Saadat Mahshid D.
Saile George O.
TriTech Microelectronics International Ltd.
Wilson Allan R.
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