Method for manufacturing attenuated phase-shift masks and devices obtained therefrom
AssigneesImec, Sony Corporation
InventorsMasaki Yoshizawa, Leonardus Leunissen
Life of this patent
Estimating the term…
Abstract
One inventive aspect relates to an attenuated phase shift mask suitable for hyper NA lithographic processing of a device, to a method of making such a mask and to hyper NA lithographic processing using such a mask. The attenuated phase shift mask is made taking into the effect of the numerical aperture of the lithographic system on which the attenuated phase shift mask is to be used.
Claims21
A method of designing an embedded attenuated phase shift mask or mask blank for use in a lithographic process, the mask or mask blank comprising a halftone stack, the mask or mask blank being suitable for off-axis illumination and/or hyper numerical aperture (NA), the method comprising
- selecting mask setting values for the phase shift mask or mask blank and process parameter values for the lithographic process, the process parameter values comprising at least a numerical aperture equal to or larger than about 1,
- selecting an image performance parameter,
- performing an aerial image simulation using the selected mask setting values and deriving from the aerial image simulation the corresponding value for the image performance parameter,
- evaluating the derived image performance parameter value with respect to a predetermined image performance parameter criterion, and
- if the derived image performance parameter does not fulfill the image performance parameter criterion, adjusting the mask setting values based on the derived image performance parameter and repeating the performing a simulation and the evaluating.
An embedded attenuated phase-shift mask comprising a transparent substrate, and a halftone stack, the halftone stack comprising an absorber material and a phase-shift material, the thickness of the absorber material and the thickness of the phase-shift material being determined taking into account off-axis illumination and taking further into account a numerical aperture equal to or larger than about 1.
A processing system, the system comprising
- an input means for receiving selected mask setting values for the phase shift mask or mask blank, selected process parameter values for the lithographic process, the process parameter values at least comprising off-axis illumination, and selected image performance parameter(s), the input means for receiving selected process parameter values being adapted for receiving selected process parameters comprising at least a numerical aperture equal to or larger than approximately 1,
- a processing means for performing an aerial image simulation using the inputted selected mask setting values and selected process parameter values and for deriving from the aerial image simulation the corresponding value for the selected image performance parameter, the processing means for performing an aerial image simulation being adapted for performing the aerial image simulation using selected process parameter values comprising at least a numerical aperture equal to or larger than approximately 1,
- an evaluation means for evaluating the derived image performance parameter with respect to a predetermined image performance parameter criterion, and
- an adjusting means for adjusting the mask setting values based on the derived image performance parameter, if the derived image performance parameter does not fulfil the image performance parameter criterion.
A processing system, comprising:
- a processor;
- and
- a program executed by the processor, comprising:
- an input module configured to receive selected mask setting values for the phase shift mask or mask blank, selected process parameter values for the lithographic process, the process parameter values at least comprising off-axis illumination, and selected image performance parameter(s), the input module being adapted for receiving selected process parameters comprising at least a numerical aperture equal to or larger than about 1,
- a processing module configured to perform an aerial image simulation using the inputted selected mask setting values and selected process parameter values and to derive from the aerial image simulation the corresponding value for the selected image performance parameter, the processing module being adapted for performing the aerial image simulation using selected process parameter values comprising at least a numerical aperture equal to or larger than about 1,
- an evaluating module configured to evaluate the derived image performance parameter with respect to a predetermined image performance parameter criterion, and
- an adjusting module configured to adjust the mask setting values based on the derived image performance parameter, if the derived image performance parameter does not fulfill the image performance parameter criterion.
Dependencies are inferred from the claim text.