| 摘要 |
An exposure apparatus comprises a metrology frame that supports a projection optical system, a first drive system that drives a first stage, a second drive system that drives a second stage, a first encoder system that measures positional information of the first stage, a second encoder system having four heads and measures positional information of the second stage, and a controller. The controller controls the first drive system based on measurement information of the first encoder system and the second drive system based on measurement information of the second encoder system for scanning exposure of a substrate. The controller also controls the second drive system based on correction information for compensating for a measurement error of the second encoder system which occurs due to performing drive control of the second stage and positional information. |
| 主权项 |
1. An exposure apparatus that exposes a substrate with illumination light via a projection optical system, the apparatus comprising:
a body that has a metrology frame to support the projection optical system; a first stage that is disposed above the projection optical system and holds a mask illuminated with the illumination light; an illumination optical system that has a masking system and an optical integrator, the masking system setting an illumination area irradiated with the illumination light on the mask, and the optical integrator substantially unifomizing intensity of the illumination light in the illumination area; a first drive system that has a linear motor to drive the first stage; a first encoder system that measures positional information of the first stage; a base member disposed below the projection optical system and supported via a plurality of vibration isolation mechanisms; a second stage that is disposed on the base member and has a holder to hold the substrate; a second drive system that has a planar motor of a magnetic levitation type and drives the second stage, the planar motor supporting the second stage by levitation on the base member; a second encoder system that has four heads provided at the second stage and measures positional information of the second stage, each of the four heads irradiating a scale member from below with a measurement beam, the scale member having four sections and an opening surrounded by the four sections, and each of the four sections having a reflection-type grating formed; and a controller that is coupled to the first and the second drive systems, and controls the first drive system based on measurement information of the first encoder system and also controls the second drive system based on measurement information of the second encoder system for scanning exposure of the substrate, in the scanning exposure the mask being moved relative to the illumination area and also the substrate being moved relative to an exposure area on which a pattern image in the illumination area is projected via the projection optical system, wherein the scale member is provided at the metrology frame so that the projection optical system is located in the opening and the scale member is disposed on a lower end side of the projection optical system, the four heads are provided at the second stage so that a distance between two heads of the four heads is larger than a width of the opening, the controller controls the second drive system so that the second stage is moved in a movement area that includes a first area and four second areas, in the first area the four heads respectively facing the four sections, and each of the four second areas having a part different from the first area, controls the second drive system so that the second stage is moved from one second area of the four second areas to another second area, different from the one second area, of the four second areas, via the first area, in the one second area, three heads of the four heads respectively facing three sections of the four sections, and in the another second area, three heads consisting of another head and two heads respectively facing three sections consisting of another section and two sections, the another head being of the four heads and being different from the three heads used in the one second area, the two heads being of the three heads used in the one second area, the another section being of the four sections and being different from the three sections used in the one second area, and the two sections being of the three sections used in the one second area, and controls the second drive system based on correction information for compensating for a measurement error of the second encoder system and positional information measured with the three heads used in the another second area, in order to move the second stage in the another second area, the measurement error of the second encoder system occurring due to performing drive control of the second stage by the three heads used in the another second area, instead of drive control of the second stage by the three heads used in the one second area, and the correction information is acquired from positional information obtained from the four heads while the second stage is in the first area. |
