Programming methods for phase-change memory

Set pulses with finite rise time that heat up phase change alloy between about nucleation temperature and about average of crystallization and melting temperatures are proposed for programming phase change memory from reset to set state in order to minimize energy during this transition and to achieve uniform set state distribution. Non-square reset pulses with finite rise time that heat up phase change alloy at or above melting temperature are proposed for programming phase change memory from set to reset state in order to improve cell endurance.