Controlling the TCR of thin film resistors

Abstract

We demonstrate that the temperature coefficient of resistance (TCR) of NiCr thin film resistors can be effectively controlled by changing the film thickness over a certain range. We have observed a direct dependency between TCR and sheet resistance, which can be expressed by the equation: TCR(in ppm/C)=525*exp(-0.01*sheet (in Ohms/sq)). This behavior can be explained by considering the transition from a bulk conductivity mechanism to a mechanism dominated by charge carrier creation and tunneling between metallic islands.

TCR control of Ni–Cr resistive film deposited by DC magnetron sputtering

“…Among these materials, Ni-Cr alloy has been especially developed as a thin film resistor, since it possesses high electrical resistivity and low TCR performance [13]. Lixin Zhao and Philipp Steinmann investigate the resistive film thickness dominating the resistivity and TCR performance that is related to the electron mean free path (MFP) [8,11]. However, a systematic research on determining the electron mean free path (MFP) of Ni-Cr film corresponding to electrical performance has not yet been reported, regarding the optimal combination to achieve reliable TCR characteristics.…”

“…Thin film resistors are generally used for electronic circuits because of their high stability, narrow tolerance and low TCR; therefore, various researches and developments have been reported which focus on the resistor material compositions such as NiCr, SiCr and TaN; the fabrication process includes various sputtering conditions and annealing temperatures [2][3][4][5][6][7][8][9][10][11][12]. Among these materials, Ni-Cr alloy has been especially developed as a thin film resistor, since it possesses high electrical resistivity and low TCR performance [13].…”

The effect of microstructures on the electrical properties of Cr–Si–C thin film resistors

“…As highly integrated circuits are developed, both higher resistivity and lower absolute TCR are required for high-precision circuits with smaller size and smaller temperature drift characteristics. Currently, various metal-based materials such as NiCr, [1][2][3][4][5] TaN, [6][7][8] Ta 2 N, 9) TiN, 10,11) and CuNi 12,13) are proposed for TFRs. Near-zero TCR values of less than 50 ppm °C−1 have been reported for some metalbased TFRs; however, their resistivity is a low value of less than 0.3 mΩ•cm.…”

Annealing effect on the electrical properties and composition of a NiCrAl thin film resistor

“…A thin film resistor is an important component required for high precision and a low temperature coefficient of resistance (TCR). [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The most common technology used to produce a thin film resistor is magnetron sputtering in which target composition and quality play important roles in dominating the performance of a thin film resistor. 16) Typically a Ni-Cr alloy is chosen as the target material of a thin film resistor due to its high reliability and long term stability.…”