Shutter device, method of controlling same, photolithography machine, and method of controlling exposure dose thereof

A method of controlling a shutter device, the shutter device comprising:

• a voice coil motor, comprising:
• a permanent magnet module;
• a guide track assembly;
• and
• a coil assembly, arranged on the guide track assembly;
• and
• a light blocking unit, comprising:
• two shutter blades, connecting to the coil assembly;
• wherein, the permanent magnet module is configured to produce a magnetic field in the guide track assembly;
• the coil assembly is configured to, when energized, produce a magnetic field having a direction same as or opposite to a direction of the magnetic field in the guide track assembly, so that the coil assembly moves forward or backward along the guide track assembly to drive the two shutter blades to open or close, and directions of current in the coil assembly is changed to control speeds at which the two shutter blades are opened or closed;
• wherein a shaft-bearing assembly is arranged between the shutter blades and the coil assembly, and the shaft-bearing assembly comprises a bearing seat, a shaft mounted on the bearing seat, bearings attached to the shaft and sleeves fitted over the bearings, and wherein the shutter blades are sheathed over the shaft and connected to the coil assembly;
• wherein each of the shutter blades has a center of gravity that is in vicinity of a center of the shaft and is closer to a curved edge of the shutter blade;
• and
• the method comprising:
• determining an output force of the voice coil motor based on a size of a desired light spot;
• and
• determining a current output from a control board to the coil assembly, based on the output force of the voice coil motor;
• wherein the control board is configured to output, to the coil assembly, a forward current to accelerate movements of the shutter blades and a backward current to decelerate movements of the shutter blades so that the shutter blades can be opened and closed in a cycle consists of four phases:
• acceleration for opening, deceleration for opening, acceleration for closure and deceleration for closure, each lasting for a defined energizing time duration.

An exposure dose control method for use with a photolithography machine comprising a shutter device, the shutter device comprising:

• a voice coil motor, comprising:
• a permanent magnet module;
• a guide track assembly;
• and
• a coil assembly, arranged on the guide track assembly;
• and
• a light blocking unit, comprising:
• two shutter blades, connecting to the coil assembly;
• wherein, the permanent magnet module is configured to produce a magnetic field in the guide track assembly;
• the coil assembly is configured to, when energized, produce a magnetic field having a direction same as or opposite to a direction of the magnetic field in the guide track assembly, so that the coil assembly moves forward or backward along the guide track assembly to drive the two shutter blades to open or close, and directions of current in the coil assembly is changed to control speeds at which the two shutter blades are opened or closed;
• wherein a shaft-bearing assembly is arranged between the shutter blades and the coil assembly, and the shaft-bearing assembly comprises a bearing seat, a shaft mounted on the bearing seat, bearings attached to the shaft and sleeves fitted over the bearings, and wherein the shutter blades are sheathed over the shaft and connected to the coil assembly;
• wherein each of the shutter blades has a center of gravity that is in vicinity of a center of the shaft and is closer to a curved edge of the shutter blade;
• and
• the method comprising:
• receiving an instruction indicative of an exposure dose, based on which, an output force of the voice coil motor is determined;
• and based on the output force of the voice coil motor, determining an current output from the control board to the coil assembly and energizing time durations of the coil assembly for a single exposure dose control cycle consisting of actions of:
• acceleration for opening of the shutter device, under an effect of a forward current output by the control board to the coil assembly;
• subsequent to completion of the acceleration action, deceleration for opening of the shutter device, under an effect of a backward current output by the control board to the coil assembly;
• subsequent to completion of the deceleration action, standby of the shutter device, under an effect of a holding current output by the control board to the coil assembly;
• acceleration for closure of the shutter device, under an effect of a forward current output by the control board to the coil assembly in response to a closing instruction given upon the satisfaction of an time-energy criterion;
• and subsequent to completion of the acceleration action, deceleration for closure of the shutter device, under an effect of a backward current output by the control board to the coil assembly.