Manager, Advanced Technology Group, Research and Development Department, Mostek Corp., Carrollton, Texas
Pages: 13 Published: Jan 1980
Transient capacitance measurements performed on the storage capacitors of dynamic metal oxide semiconductor (MOS) random access memory (RAM) circuits can be used to determine dynamic storage time, because the decay phenomenon is equivalent to the operation of the circuit. Therefore, transient capacitance measurements can be used as a yardstick for process improvements that lengthen storage time and improve the refresh time margin. By analyzing the transient response, using the classic Zerbst technique, the minority carrier lifetime can be determined. In addition, an extension of Heiman's theoretical analysis to include a constant contribution to the leakage currents from process-induced damage and diffusion current from the substrate gives a solution for the capacitive transient that is in excellent agreement with the experimental curves. The T and K parameters in this solution are related to the minority carrier lifetime, τ, and the constant leakage carrier generation density, g, and the values of these parameters can be determined from the Zerbst slope and intercept. For K = g = 0, the solutions reduce to those of Heiman.
damage, defects, diffusion current, dynamic random access memory (RAM) circuits, dynamic storage, gated diode, generation current, guard-ring capacitor, minority carrier lifetime, metal oxide semiconductor (MOS) process improvement, metal oxide semiconductor (MOS) pulse capacitor analysis, metal oxide semiconductor (MOS) recovery time, metal oxide semiconductor (MOS) storage time, metal oxide semiconductor (MOS) transient capacitance, one-transistor random access memory (RAM) circuits, refresh time, Zerbst analysis, silicon
Paper ID: STP35127S