Manufacturing method for low temperature polycrystalline silicon thin film transistors

The present invention provides a manufacturing method for low temperature polycrystalline silicon thin film transistors, and the method is characterized by including the following steps: a polycrystalline silicon layer, a gate insulation layer and a gate metal layer are formed on a substrate in sequence; one part of the gate metal layer is removed so as to expose one part of the gate insulating layer; and doping ions penetrate the exposed part of the gate insulation layer by the adoption of an ion-injection method. According to the invention, a metal layer is etched only but a silicon nitride and silicon oxide layer is not etched, a dose uniformity of the doping ion injecting is increased, and therefore, an electricity uniformity of the low temperature polycrystalline silicon thin film transistors is improved.