The application of a phenomenological depth‐dose theory to the exposure of negative electron resists is described in detail. The model predicts a cross‐linking ratednc/dt=(Gc/100) × (J0/e)(Va/RG)&Lgr;(f) cm−3sec−1, whereGcis the number of crosslinks produced per 100 eV lost in the polymer.Jois the incident current density,Vathe initial kinetic energy,RGthe electron Grun range, and &Lgr;(f) the depth‐dose function in terms of the normalized penetrationf=z/RG. Since theGvalue of a negative resist decreases with exposure, it is suggested that a more meaningful parameter characterizing a negative resist is the absorbed energy required to gel the polymer at the resist‐substrate interface. This interface or threshold gel energy density,Eg(i), is independent of the beam parameters and varies from about 1022eV cm−3for polyvinyl ferrocene to 3.8×1018eV cm−3for epoxidized polybutadienes. The model predicts that the threshold sensitivity should vary asVa0.75which agrees reasonably well with published experimental values. It also predicts that at a given accelerating voltage, there is a unique initial resist thickness at which the top surface and interface receive identical doses. This unique thickness turns out to be roughly the electron diffusion rangeRD. The transverse resolution or linewidth for negative resists has been investigated as a function of accelerating voltage and found to be given by twice the diffusion range. SinceRDdecreases with decreasingVa, the linewidth likewise decreases as the accelerating voltage is lowered. The optimum operating conditions for a 500‐nm resist film for electron lithography are predicted to beVa≈5 kV exposed to yield about a 400‐nm film after development. It should be noted that these conditions result in a maximum crosslink density per incident electron and a minimum linewidth. However, there may be specific applications where other sets of operating conditions are useful. A geometric model is suggested which appears to account for the observed behavior of sensitivity of negative resists.