Patent attributes
In a stealth dicing process for a semiconductor device with a low dielectric constant layer, the occurrence of poor appearance such as a defective shape or discoloration in the layer is reduced or prevented as follows. A low dielectric constant layer is formed in an interlayer insulating layer formed on the main surface of a semiconductor wafer. A laser beam is focused on the inside of the wafer from the reverse side of the wafer in order to form modified regions selectively. Each modified region is formed in a way to contact, or partially get into, the low dielectric constant layer. In this formation process, the semiconductor wafer is cooled by a cooling element. This reduces or prevents discoloration of the low dielectric constant layer which might occur due to the heat of a laser beam.