A first stage system having a first stage and a first drive system that moves the first stage is configured to hold a mask illuminated with illumination light. A second stage system having a second stage and a second drive system that moves the second stage is configured to hold a substrate. A measurement system having a first encoder system and a second encoder system measures positional information of the first and second stages, respectively. The second encoder system measures the positional information of the second stage with a plurality of heads that face a grating section. The first and second drive systems are controlled based on correction information for compensating for a measurement error of the second encoder system that occurs due to the heads and measurement information of the first and the second encoder systems.

In an exposure apparatus and a method for defocus and tilt error compensation, each of alignment sensors (500a, 500b, 500c, 500d, 500e, 500f) corresponds to and has the same coordinate in the first direction as a respective one of focusing sensors (600a, 600b, 600c, 600d, 600e, 600f), so that each of the alignment sensors (500a, 500b, 500c, 500d, 500e, 500f) is arranged on the same straight line as a respective one of the focusing sensors (600a, 600b, 600c, 600d, 600e, 600f). As such, alignment marks can be characterized with both focusing information and alignment information. This enables the correction of errors in the alignment information and thus achieves defocus and tilt error compensation, resulting in significant improvements in alignment accuracy and the production yield.

A movement area of a stage includes first-fifth areas. In the first area, three of four heads except for a first head respectively face three of four sections of a scale member except for a first section. In the second area, three of four heads except for a second head respectively face three of four sections except for a second section of the scale member. In the third area, three of four heads except for a third head respectively face three of four sections except for a third section of the scale member. In the fourth area, three of four heads except for a fourth head respectively face three of four sections of the scale member. In the fifth area, the four heads respectively face the four sections. The stage is moved from one of the first-fourth areas to another of those areas via the fifth area.

A measurement system for a lithographic apparatus includes a sub-frame compliantly mounted on a reference frame. A measurement device, e.g. an alignment sensor, is mounted on the sub-frame. Soft mounting of the sub-frame isolates the alignment sensor from high-frequency disturbances, e.g. acoustic noise, by acting as a low-pass filter with a cut-off frequency, e.g. in the range of from 100 to 200 Hz.

There is disclosed a method of measuring a process parameter for a manufacturing process involving lithography. In a disclosed arrangement the method comprises performing first and second measurements of overlay error in a region on a substrate, and obtaining a measure of the process parameter based on the first and second measurements of overlay error. The first measurement of overlay error is designed to be more sensitive to a perturbation in the process parameter than the second measurement of overlay error by a known amount.

Within area where of four heads installed on a wafer stage, heads included in the first head group and the second head group to which three heads each belong that include one head different from each other face the corresponding areas on a scale plate, the wafer stage is driven based on positional information which is obtained using the first head group, as well as obtain the displacement (displacement of position, rotation, and scaling) between the first and second reference coordinate systems corresponding to the first and second head groups using the positional information obtained using the first and second head groups. By using the results and correcting measurement results obtained using the second head group, the displacement between the first and second reference coordinate systems is calibrated, which allows the measurement errors that come with the displacement between areas on scale plates where each of the four heads face.

Within area where of four heads installed on a wafer stage, heads included in the first head group and the second head group to which three heads each belong that include one head different from each other face the corresponding areas on a scale plate, the wafer stage is driven based on positional information which is obtained using the first head group, as well as obtain the displacement (displacement of position, rotation, and scaling) between the first and second reference coordinate systems corresponding to the first and second head groups using the positional information obtained using the first and second head groups. By using the results and correcting measurement results obtained using the second head group, the displacement between the first and second reference coordinate systems is calibrated, which allows the measurement errors that come with the displacement between areas on scale plates where each of the four heads face.

Within area where of four heads installed on a wafer stage, heads included in the first head group and the second head group to which three heads each belong that include one head different from each other face the corresponding areas on a scale plate, the wafer stage is driven based on positional information which is obtained using the first head group, as well as obtain the displacement (displacement of position, rotation, and scaling) between the first and second reference coordinate systems corresponding to the first and second head groups using the positional information obtained using the first and second head groups. By using the results and correcting measurement results obtained using the second head group, the displacement between the first and second reference coordinate systems is calibrated, which allows the measurement errors that come with the displacement between areas on scale plates where each of the four heads face.

Methods for in-die overlay reticle measurement and the resulting devices are disclosed. Embodiments include providing parallel structures in a first layer on a substrate; determining measurement sites, in a second layer above the first layer, void of active integrated circuit elements; forming overlay trenches, in the measurement sites and parallel to the structures, exposing sections of the structures, wherein each overlay trench is aligned over a structure and over spaces between the structure and adjacent structures; determining a trench center-of-gravity of an overlay trench; determining a structure center-of-gravity of a structure exposed in the overlay trench; and determining an overlay parameter based on a difference between the trench center-of-gravity and the structure center-of-gravity.

An alignment optical measurement element includes a grating coupler, and a reflector coupled to the grating coupler. The alignment optical measurement element is arranged so that: the grating coupler diffracts an incident light in a first direction into a first diffracted light to propagate the first diffracted light as a first propagating light in a second direction, the reflector reflects the first propagating light into a second propagating light in a third direction opposite to the second direction; and the grating coupler diffracts the second propagating light into a second diffracted light to emit the second diffracted light as an emitted light in a fourth direction opposite to the first direction.