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Capacitor Extended Subcollector and Extended Transistor Subcollector

IP.com Disclosure Number: IPCOM000075683D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Gates, HR: AUTHOR [+3]

Abstract

Capacitor structures are shown which substantially conserves area in an integrated circuit product. Preferably, the N+ diffusions of either an emitter or subcollector is extended into an isolation region which is P+ doped, to give a highly packed capacitor arrangement.

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Capacitor Extended Subcollector and Extended Transistor Subcollector

Capacitor structures are shown which substantially conserves area in an integrated circuit product. Preferably, the N+ diffusions of either an emitter or subcollector is extended into an isolation region which is P+ doped, to give a highly packed capacitor arrangement.

The Figs. A, B, C, and D show various alternate structures wherein the ohmic contact metallurgy is 1, the glass passivation is 2, the N+ emitter is 3, the P base is 4, the P+ isolation is 5, the N epitaxial layer is 6, the N+ subcollector is 7, and the P- substrate is 8.

Figs. Aa and Ab show the extension of the N+ subcollector 7 under the surrounding P+ isolation to form the back-biased diode junction capacitor, between the P+ isolation structure (cathode) 5 and the N+ subcollector (anode)
7. Fig. B shows the extension of subcollector 7 of a transistor under the surrounding isolation 5, to form the back-biased diode capacitor from positive to ground. Figs. C and D show the N+ emitter can be extended in any or all of the other three dimensions, providing the minimum spacing of P base 4 to N+ emitter 3 is maintained. The extended emitters 3 of Figs. C and D have been made with a breakdown voltage above 5 volts, and the junction has a leakage current below 10 microamps. In Figs. A, B and C the P+ isolation is connected to ground through a metallurgy layer, which is not shown in the drawings, and the N+ subcollector is shown extended...