The authors have investigated the effects of elevated substrate temperature (T-s) on cleaning of boron residues from silicon substrates in 1%H-2-Ar plasmas, following etching of HfO2 in BCl3 plasmas. Vacuum-transfer x-ray photoelectron spectroscopy (XPS) provided a measure of total B removal rates, as well as information on individual BClxOy moities. B cleaning rates increased with T-s in an Arrhenius manner, with an apparent activation energy of 1.7 kcal/mol. Conversely, the Si etching rate decreased with increasing substrate temperature with an apparent activation energy of -0.8 kcal/mol. Therefore, when considering selectivity with respect to Si etching, it is advantageous to remove B at higher T-s. For example, at T-s=235 degrees C, similar to 90% of B is cleaned from Si in 10 s, while < 1.5 nm of Si is removed. An apparent diffusion of H into the near-surface region of Si at higher temperatures, detected indirectly by a shift and broadening of the Si(2p) XPS peak, may limit the maximum optimum substrate temperature, however. It was also found that Si does not etch in 1%H-2/Ar plasmas if an oxide layer is present.