A polysilicon resistor with low thermal activation energy for a VLSI memory cell is formed in polysilicon by having P-type (such as boron) impurities in a middle region and n-type (such as phosphorpus or arsenic) impurities on the sides, with the concentrations being in a range so that the thermal activation energy is below about 0.5 eV. Further, the middle region can be doped additionally with arsenic or phosphorous in an amount equal to or less than the boron. This gives good leakage current masking over a range of -55° to +125°C without drawing excessive current, and is less sensitive to impurities.