A tool and a method of reflow are provided. In various embodiments, the tool includes a chamber unit, a wafer lifting system, a heater, and an exhausting unit. The wafer lifting system is disposed in the chamber unit. The heater is coupled to the chamber unit, and configured to heat the wafer. The exhausting unit coupled to the chamber unit, and configured to exhaust gas in the chamber unit. The wafer lifting system is configured to receive and move the wafer in the chamber unit, and to provide a vertical distance between the heater and the wafer in the chamber unit.