| 摘要 |
PROBLEM TO BE SOLVED: To enable effective impurity activation of an IGBT device or the like at a sufficient depth.SOLUTION: A heat treatment method for heat-treating the surface of a substrate includes the steps of: repeatedly performing overlapping irradiation onto the substrate while scanning with laser pulses having a rise time of 160 ns or more which is a time until reaching 90% of the maximum intensity of a pulse waveform from 10%, and having a ratio of the rise time relative to a fall time which is a time until reaching 10% of the maximum intensity of the pulse waveform from 90% is larger than 1; and heat-treating the substrate so that the substrate is non-fused and the process layer maintains in a non-dissolving state or that only the surface layer is fused and the process layer except for the surface layer maintains in a non-dissolving state. Thereby, the light penetration length of the pulsed laser can be larger and a target deeper region (for example, 2 μm or more) can be activated. |
