An experimental technique is described to determine the reaction image in the negative-tone, chemically amplified resist, Shipley SAL 605, for a specific set of exposure and thermal processing conditions. Isolated 0.25-mu m line formation at varying arrested development times is used in this study to assign an "effective" dose to locations within the resist through bulk dissolution rate data. This method was validated under different development conditions resulting in calculated and experimental line width agreement with an average deviation of 27 nm, and sidewall angle within 4 degrees for developer puddle times between 20 and 113 s. End-on development provides unique access to determine chemically amplified reaction processing effects by diminishing the role of development. A comparison between the arrested development and end-on developed cross-sections indicates a strong development effect contributing to the sidewall angle at various puddle times.