Vertical current components in integrated injection logic

Analytic expressions representing a double diffused transistor impurity profile are used to calculate the current components in IIL structures. The expression for the hole current is given for IIL structures with the epitaxial layer grown on a wide n⁺substrate and for buried layer structures. It was found that an equivalent recombination velocity at the n-n⁺interface, , is of order 10²higher in buried layer structures than in structures with the epitaxial layer grown on a wide n⁺substrate for comparable doping levels. Results obtained using the analytic expressions are compared with those obtained using a computer program which includes heavy doping effects and doping level mobility dependence. Both calculated and computed results are also compared with measured currents for a given IIL structure with the epitaxial layer grown on a wide n⁺substrate. The calculated and the computed results are in good agreement with the experimental results.