A method for controlling the variation in process parameters using test structures sensitized to process parameter changes. Wavefront engineering techniques are used to make features of the test structure more sensitive to process changes. Focus and exposure parameters are adjusted in response to the measurements of the test structures. In another embodiment, the wavefront engineering features are placed to permit the test structure appearing on the reticle out of focus. The wavefront engineering feature is an OPC technique applied to the test structure to modify it. The OPC features are applied in an asymmetrical manner to the test structure and enable identifying the direction of process focus changes.

Method and apparatus for the production of process sensitive lithographic features

A method for determining one or more process parameter settings of a photolithographic system is disclosed.

Method for determining lithographic focus and exposure

A method and apparatus for reducing loading effects on a semiconductor manufacturing component during an etch process is disclosed. The transmittance associated with a photomask is calculated and the etch process for a material formed on a semiconductor manufacturing component is adjusted based on the transmittance calculated for the photomask.

Method and apparatus for reducing loading effects on a semiconductor manufacturing component during an etch process

A method is described for measuring a dimension on a substrate, wherein a target pattern (455) is provided with a nominal characteristic dimension that repeats at a primary pitch of period P, and has a pre-determined variation orthogonal to the primary direction. The target pattern (455) formed on the substrate is then illuminated so that at least one non-zero diffracted order is detected. The response of the non-zero diffracted order to variation in the printed characteristic dimension relative to nominal is used to determine the dimension of interest, such as critical dimension or overlay, on the substrate. An apparatus (40) for performing the method of the present invention includes an illumination source (410), a detector (460) for detecting a non-zero diffracted order, and means for positioning the source (410) relative to the target (455) so that one or more non-zero diffracted orders from the target (455) are detected at the detector (460).

Differential critical dimension and overlay metrology apparatus and measurement method

An overlay target for spectroscopic measurement includes at least two diffraction gratings, one grating overlying the other. The diffraction gratings may include an asymmetry relative to each other in order to improve resolution of the presence as well as the direction of any mis-registration. For example, the asymmetry between the two diffraction gratings may be a phase offset, a difference in pitch, line width, etc. The overlay target may be spectroscopically measuring, for example, using an optical model and a best fit analysis. Moreover, the overlay target may be optimized by modeling the overlay target and adjusting the variable parameters and calculating the sensitivity of the overlay target to changes in variable parameters.

Spectroscopically measured overlay target

A method and apparatus for determining optical mask corrections for photolithography. A plurality of grating patterns is printed onto a wafer utilizing a photomask having at least one grating. Each grating pattern within the plurality of grating patterns is associated with known photolithographic settings. Each grating pattern is illuminated independently with a light source, so that light is diffracted off each grating pattern. The diffracted light is measured utilizing scatterometry techniques to determine measured diffracted values. The measured diffracted values are compared to values in a library to determine a profile match. A 2-dimensional profile description is assigned to each grating pattern based on the profile match. A database is compiled of the profile descriptions for the plurality of grating patterns. Photomask design rules are then generated by accessing the database containing the 2-dimensional profile descriptions. In preferred embodiments, the design rules are used to create and correct masks containing OPC corrections, phase-shifting mask corrections and binary masks. In a preferred embodiment the at least one grating is a bi-periodic grating. In a preferred embodiment, the scatterometry technique is optical digital profilometry utilizing a reflectometer or ellipsometer.

Method and apparatus for the determination of mask rules using scatterometry

PROBLEM TO BE SOLVED: To provide a method and an apparatus for determining optical mask correction for photolithography. SOLUTION: A plurality of grating patterns is printed onto a wafer by using a photomask having at least one grating. Each grating pattern within the plurality of grating patterns is associated with known photolithographic settings. Each grating pattern is illuminated independently with a light source so that light is diffracted off each grating pattern. The diffracted light is measured by utilizing scatterometry techniques in order to determine a measured diffracted value. The measured diffracted value is compared with a value in a library in order to determine a profile match. Two-dimensional profile description is allocated to each grating pattern on the basis of the profile match. A database is complied of the profile description corresponding to the plurality of grating patterns.

Nickhil H. Jakatdar

Papers

Method and apparatus for the determination of mask rules using scatterometry

Method and apparatus for determining mask rule using scatterometry

Werkwijze en inrichting voor het bepalen van optische maskerregels met gebruik van scatterometrie.