Product Structure/Modules

Product Structure
TCAD Sentaurus Lithography is structured in a modular fashion, offering high flexibility and a transparent licensing scheme to the user.

S-Litho - Base Module
The base module of Sentaurus Lithography offers editing capabilities for setting up any simulation task, from simple simulations using a “thin mask” approximation (Kirchhoff approximation) to complex simulation scenarios taking mask and wafer topography effects into account. It allows also viewing and visualizing computation results and performing additional analyses on those results, for instance evaluating process windows. Moreover, it supports the administration of a central database which acts as a repository of all simulation setup relevant information.

S-Litho - Optical Module
The optical module of Sentaurus Lithography allows state-of-the-art simulation of the optical imaging process for evaluation and optimization purposes, including immersion lithography, based on the “thin mask” approximation (Kirchhoff approximation). A physical three dimensional resist model provides high predictive power to all kind of simulation tasks. Functionality for resist model parameter calibration by fitting against experimental data is included as well.

S-Litho – MT module
As soon as the feature size on the mask level approaches the wavelength of the exposure light, the classical Kirchhoff approximation is no longer valid. Even for binary masks, mask topography effects due to the finite thickness of the absorber layer have to be taken into account: The electromagnetic field (EMF) propagating through the mask must be determined rigorously by solving Maxwell’s equations in all three dimensions, using a specially tailored and efficient FDTD (finite difference time domain) approach. Therefore, the MT module, an add-on to the optical module of Sentaurus Lithography, allows detailed studies of variance that is introduced by the mask-making process.

S-Litho – WT module
Topographic wafers are the domain of the WT module, another add-on to the optical module of Sentaurus Lithography. After the first pattern transfer steps on the wafer level, subsequent lithography processes see nonflat exposure conditions, due to either local height or reflectivity variations, which may impact the image formation on the wafer. The creation of a topographic wafer stack can be accomplished by using either the integrated 3D topography editor or the results of an external process simulation generated by the Synopsys TCAD Sentaurus products. S-Litho provides all of the necessary interfaces.

S-Litho – MP option
The MP option accelerates specific simulation tasks through parallel processing by supporting multiple CPUs or cores (threads) on shared-memory hardware systems. One MP option supports two CPUs or cores; further MP options can be added.