A method and apparatus for vaporizing liquid source materials, where such vaporized source materials are supplied to a deposition tool such as Chemical Vapor Deposition (CVD) apparatus, and more particularly in such areas as Metalorganic Chemical Vapor Deposition (MOCVD) and Atomic Layer Deposition (ALD) applications, is disclosed. The method disclosed herein involves with increasing the temperature and the pressure of given liquid source materials to a high level of temperature and pressure states while maintaining the source materials in a liquid state, and then exposing the liquid source material instantaneously to a low pressure while maintaining the temperature of the liquid source material at the high temperature. Such sudden exposure to a low pressure makes the liquid source material vaporized, so that such vaporized source material can be supplied to such deposition tools as Metalorganic Chemical Vapor Deposition (MOCVD) and Atomic Layer Deposition (ALD) apparatus. The structure and the operation of the apparatus that vaporizes liquid source materials in accordance with the present invention are also disclosed.