A Transient Technique to Measure the Temperature Coefficient of Resistance for Thin Film Resistors

1989 ◽  
Vol 111 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Bahgat Sammakia ◽  
Phillip Vadala ◽  
Thomas Homa
Keyword(s):  
Thin Film ◽  
Temperature Coefficient ◽  
Room Temperature ◽  
Conventional Technique ◽  
Temperature Coefficient Of Resistance ◽  
Moderate Amount ◽  
Transient Technique ◽  
Thin Film Resistors ◽  
Higher Temperature ◽  
Good Agreement

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.

Stable thin film resistors using double layer structure

1995 ◽  
Vol 10 (6) ◽  
pp. 1523-1528 ◽  
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.

Metastable Phenomena in the Thermally Activated Conductivity of Hydrogenated Amorphous Germanium (a-Ge:H)

1993 ◽  
Vol 297 ◽  
Author(s):  
T. DrÜsedau ◽  
D. Pang ◽  
E. Sauvain ◽  
P. Wickboldt ◽  
E.Z. Liu ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Room Temperature ◽  
Equilibrium Temperature ◽  
Cooling Curves ◽  
Thermally Activated ◽  
Heating And Cooling ◽  
Higher Temperature ◽  
Hydrogenated Amorphous ◽  
Hydrogenated Amorphous Germanium ◽  
Good Agreement

The activated conductivity of a-Ge:H between room temperature and 460K was investigated using heating and cooling rates in the range between .001 and 0.1 K/s. A splitting of the cooling curves obtained at different rates, which defines the so called equilibrium temperature TE, is observed mainly between 420 and 430K. Taking into consideration that TE depends on the maximum cooling rate, the present results are in good agreement with those reported by Eberhardt et al. The higher cooling rate always leads to the lower conductivity at any temperature below TE. These effects can be rationalized in terms of a reversible shift of the Fermi level towards midgap at higher temperature. Though reversible changes of the mobility cannot be excluded, they cannot account for our set of experimental data. Rather, changes in the density of electronic states within the mobility gap can explain the effects observed.

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