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Browse Prior Art Database

Merged Junction Field Effect Resistor

IP.com Disclosure Number: IPCOM000089755D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Bergeron, DL: AUTHOR [+2]

Abstract

This device incorporates an ion-implanted (I/I) resistor, a Schottky barrier diode (SBD) and an N+ collector contact to form a junction field-effect resistor (JFER) for use in integrated circuits, to provide a variable resistor load with no additional process/mask steps.

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Merged Junction Field Effect Resistor

This device incorporates an ion-implanted (I/I) resistor, a Schottky barrier diode (SBD) and an N+ collector contact to form a junction field-effect resistor (JFER) for use in integrated circuits, to provide a variable resistor load with no additional process/mask steps.

The JFER is formed in the silicon substrate 1, in a region defined by thick oxide layer 3, without the use of additional masks or implants or other process steps beyond those required for conventional nitride passivated transistors and I/I resistors. The structure is shown in Fig. 1, where the channel is comprised of the N- epitaxial region 2. The positive or drain contact 4 to the channel 2 is through the SBD. Three lateral sides of the channel 2 are defined by the conventional P+ base diffusion 6. The bottom of the channel 2, the JFER gate, is formed by the implanted resistor 8. The low end or source of the JFER is defined by the N+ collector contact 10. A MOS (metal oxide semiconductor) gate 12 over thin oxide layer 14 can also be used to help in pinching off the channel 2. The circuit schematic for this structure is shown in Fig. 2, where the SBD terminal 16 is connected to a reference potential and the JFER output terminal 18 is connected to the collector of active NPN transistor 20 whose emitter is connected to ground. This inverter circuit will invert a signal at the input 22 and output it at
18.

The oxide thicknesses over the I/I resistor and over the...