Fixing hidden problems with thermal budget

Kinetic effects in rapid thermal processing (RTP) are often assessed using the concept of thermal budget. Although thermal budget can be defined in several ways, the basic premise asserts that budget minimization should minimize dopant diffusion and interface degradation. The present work highlights serious shortcomings with this principle. Experiments show that budget minimization, according to some definitions, can actually worsen diffusion problems rather than mitigate them. We present a straightforward framework for improving the results through comparison of activation energies of the desired and undesired phenomena. This framework provides strong kinetic arguments for continued development of rapid isothermal processing and small batch fast ramp methods.