Cubic BAs is used in semiconductors to improve the thermal characteristics of a device. The BAs is used in device layers to improve thermal conductivity. The BAs also provides thermal expansion characteristics that are compatible with other semiconductors and thereby further improves reliability. The substrates of the semiconductors may also include vias that contain BAs. The BAs in the vias may contact the BAs in the device layers. Some vias may have a surface area to volume ratio of greater than 10 to better assist with device heat dissipation.