Laser irradiation apparatus, laser irradiation method, and method of manufacturing semiconductor device

A laser irradiation apparatus, comprising:

• a laser generating device configured to generate a laser beam;
• and
• a flotation unit configured to cause a workpiece to float, the workpiece being to be irradiated with the laser beam, wherein
• the flotation unit includes a first region and a second region,
• the first region and the second region are disposed so that, as viewed in a plan view, a focal point of the laser beam is superposed on the first region and the focal point of the laser beam is not superposed on the second region,
• the first region is configured to cause the workpiece to float by utilizing ejection and suction of a gas, and
• the second region is configured to cause the workpiece to float by utilizing ejection of a gas, and
• a flatness of a surface of the first region that opposes the workpiece is smaller than a flatness of a surface of the second region that opposes the workpiece.

A laser irradiation apparatus, comprising:

• a laser generating device configured to generate a laser beam;
• and
• a flotation unit configured to cause a workpiece to float, the workpiece being to be irradiated with the laser beam, wherein
• the flotation unit includes a first region and a second region,
• the first region and the second region are disposed so that, as viewed in a plan view, a focal point of the laser beam is superposed on the first region and the focal point of the laser beam is not superposed on the second region,
• the first region is configured to cause the workpiece to float by utilizing ejection and suction of a gas, and
• the second region is configured to cause the workpiece to float by utilizing ejection of a gas,
• a flatness of a surface of the first region that opposes the workpiece is smaller than a flatness of a surface of the second region that opposes the workpiece, and
• a deflection amount of the workpiece held when the workpiece passes through the first region is smaller than the deflection amount of the workpiece held when the workpiece passes through the second region.

A laser irradiation method of irradiating a workpiece with a laser beam while the workpiece is being made to float with the use of a flotation unit, wherein

• the flotation unit includes a first region and a second region, the first region being superposed on a focal point of the laser beam as viewed in a plan view, the second region not being superposed on the focal point of the laser beam as viewed in a plan view,
• a flatness of a surface of the first region that opposes the workpiece is smaller than a flatness of a surface of the second region that opposes the workpiece, and
• when the workpiece is conveyed with the use of the flotation unit,
• the first region conveys the workpiece while causing the workpiece to float by utilizing ejection and suction of a gas, and
• the second region conveys the workpiece while causing the workpiece to float by utilizing ejection of a gas without suction of a gas.

A method of manufacturing a semiconductor device, the method comprising steps of:

• (a) forming an amorphous film over a substrate;
• and
• (b) irradiating the amorphous film with a laser beam to crystalize the amorphous film, wherein
• the step of (b) is a step of irradiating the amorphous film with the laser beam while conveying the substrate caused to float with the use of a flotation unit,
• the flotation unit includes a first region and a second region, the first region being superposed on a focal point of the laser beam as viewed in a plan view, the second region not being superposed on the focal point of the laser beam as viewed in a plan view,
• a flatness of a surface of the first region that opposes the substrate is smaller than a flatness of a surface of the second region that opposes the substrate, and
• when the substrate is conveyed with the use of the flotation unit,
• the first region conveys the substrate while causing the substrate to float by utilizing ejection and suction of a gas, and
• the second region conveys the substrate while causing the substrate to float by utilizing ejection of a gas without suction of a gas.

A laser irradiation method of irradiating a workpiece with a laser beam while the workpiece is being made to float with the use of a flotation unit, wherein

• the flotation unit includes a first region and a second region, the first region being superposed on a focal point of the laser beam as viewed in a plan view, the second region not being superposed on the focal point of the laser beam as viewed in a plan view,
• a flatness of a surface of the first region that opposes the workpiece is smaller than a flatness of a surface of the second region that opposes the workpiece,
• when the workpiece is conveyed with the use of the flotation unit,
• the first region conveys the workpiece while causing the workpiece to float by utilizing ejection and suction of a gas, and
• the second region conveys the workpiece while causing the workpiece to float by utilizing ejection of a gas, and
• a deflection amount of the workpiece held when the workpiece passes through the first region is smaller than the deflection amount of the workpiece held when the workpiece passes through the second region.

A method of manufacturing a semiconductor device, the method comprising steps of:

• (a) forming an amorphous film over a substrate;
• and
• (b) irradiating the amorphous film with a laser beam to crystalize the amorphous film, wherein
• the step of (b) is a step of irradiating the amorphous film with the laser beam while conveying the substrate caused to float with the use of a flotation unit,
• the flotation unit includes a first region and a second region, the first region being superposed on a focal point of the laser beam as viewed in a plan view, the second region not being superposed on the focal point of the laser beam as viewed in a plan view,
• a flatness of a surface of the first region that opposes the substrate is smaller than a flatness of a surface of the second region that opposes the substrate,
• when the substrate is conveyed with the use of the flotation unit,
• the first region conveys the substrate while causing the substrate to float by utilizing ejection and suction of a gas,
• the second region conveys the workpiece while causing the workpiece to float by utilizing ejection of a gas, and
• a deflection amount of the workpiece held when the workpiece passes through the first region is smaller than the deflection amount of the workpiece held when the workpiece passes through the second region.