A micro heat pipe, formed in a semiconductor substrate, carries heat from a region of heat flux in the substrate to a region of lower heat flux. The micro heat pipe is formed by cutting a groove into the substrate opposite a site where devices have been formed or are to be formed. Vapor deposited layers are then formed on the substrate to define the micro heat pipe. A fraction of the pipe is filled with a coolant or other working fluid and the pipe is sealed. A micro heat pipe may also be formed by etching a channel down into the substrate, oxidizing the surfaces of the channel, charging the channel with a cooling medium to fill a fraction of the channel and sealing the end of the channel. In operation, the working fluid evaporates in the region of high heat flux and condenses in the region of lower heat flux resulting in the transfer or redistribution of the fluid's heat of vaporization.
