Hydrogen and oxygen plasma effects on undoped and n-p compensation-doped single- and multilayer polycrystalline silicon resistor films

In this study, we investigate hydrogen and oxygen plasma effects on undoped and n-p compensation-doped polycrystalline silicon (poly-Si) resistors. The current-voltage (I-V) characteristics, channel resistance (R_p), contact region resistance (R_j), total resistance (R_T = R_p + R_j), and activation energy of the poly-Si resistors with different film lengths and passivation layers were measured and analyzed. It is found that the film resistance has been strongly enhanced by either hydrogen or oxygen plasma treatments, which is attributed to the neutralization effect of plasma treatment inside the grain being overridden by the passivation effect at the grain boundary. Moreover, it is seen that both the total resistance and activation energy of undoped intrinsic films are larger than those of n-p compensation-doped films. To realize a high-value poly-Si resistor, a novel multilayer structure is proposed for the first time. Compared with the conventional single-layer structure, it is seen that the relatively smaller grain size in a four-layer structure results in an approximately 25-50% increase in resistance.