Achievement of zero temperature coefficient of resistance with RuOx thin film resistors

The temperature coefficient of resistance (TCR) is defined as: TCR=(R2−R1)R1×1(t2−t1) where R2 and R1 are the resistances measured at temperatures t1 and t2, respectively. The conventional TCR measurement method consists of measuring resistance at room temperature, then heating the resistor to a known higher temperature, then measuring the resistance again. This technique is very accurate and repeatable, however it is slow and cumbersome because it takes a moderate amount of time for the sample to reach steady state in an oven before the resistance can be measured. The present study proposes a new transient technique for measuring TCR. Thin film resistors are heated by passing a constant electric current through them. At an arbitrarily set time, the resistor temperature is estimated from the known transient conduction solution for a uniform flux surface imbedded in a semi-infinite medium. Measurements of the resistance at that time, along with the resistance at the initial (usually room) temperature will now permit the calculation of TCR. The method was found to be very fast, repeatable, and in good agreement with the conventional technique.

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Ti/Ni(80%)Cr(20%) Thin-Film Resistor With a Nearly Zero Temperature Coefficient of Resistance for Integration in a Standard CMOS Process

IEEE Electron Device Letters ◽

10.1109/led.2007.915384 ◽

2008 ◽

Vol 29 (3) ◽

pp. 212-214 ◽

Cited By ~ 12

Author(s):

D. Nachrodt ◽

U. Paschen ◽

A. ten Have ◽

H. Vogt

Keyword(s):

Thin Film ◽

Temperature Coefficient ◽

Cmos Process ◽

Zero Temperature ◽

Temperature Coefficient Of Resistance ◽

Film Resistor ◽

Thin Film Resistor ◽

Standard Cmos Process

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Stable thin film resistors using double layer structure

Journal of Materials Research ◽

10.1557/jmr.1995.1523 ◽

1995 ◽

Vol 10 (6) ◽

pp. 1523-1528 ◽

Cited By ~ 9

Author(s):

Q.X. Jia ◽

H.J. Lee ◽

E. Ma ◽

W.A. Anderson ◽

F.M. Collins

Keyword(s):

Thin Film ◽

Temperature Coefficient ◽

Layer Structure ◽

Ruthenium Oxide ◽

Tantalum Nitride ◽

Ex Situ ◽

Temperature Coefficient Of Resistance ◽

Layer Thickness Ratio ◽

Power Loading ◽

Thin Film Resistors

Highly stable bilayer thin film resistors, which consist of an underlying layer of tantalum nitride and of a capping layer of ruthenium oxide, were developed by taking advantage of the desired characteristics of two different materials in a single system. The resistors fabricated in such a way were highly stable under power loading or thermal cycling. Resistors with one digit temperature coefficient of resistance (TCR) could be easily controlled by the layer thickness ratio of the tantalum nitride to the ruthenium oxide and the ex situ annealing temperature or duration. Auger electron spectroscopy depth profile on the thin films indicates that the ruthenium oxide layer is well defined for the as-deposited form. Nevertheless, interdiffusion takes place after thermal treatment of the bilayer which is used to tune the temperature coefficient of resistance and to stabilize the resistance of the resistors.

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