SEMulator3D News

3-D Process Modeling - A Novel and Efficient Tool for MEMS Foundry Design Support

Abstract – In this paper (click here to download) we describe a novel tool for modeling the fabrication of MEMS and semiconductor devices, and show some examples of its application in the MEMS foundry business. The tool allows an accurate visualization of the step-by step creation of the final 3-D device geometry by using the 2-D layout and a description of the fabrication process. The novelty of the tool lies in its use of voxels (3-D pixels) rather than conventional 3-D CAD techniques to represent the 3-D geometry. The tool creates highly realistic, 3-D virtual prototypes of micro-fabricated devices. Examination of these virtual prototypes can reveal design errors as well as the impact of design changes and process variations before each mask tape out and fab run, potentially reducing or eliminating design-fabricate- test cycles. To demonstrate the value of this tool to a foundry, the paper describes how the tool has been applied to a MEMS SOI micromachining process. Two detailed case studies are provided: a 3-D design check that revealed a design flaw before fabrication, and an analysis of a process failure which confirmed the suspected cause of undesired pocket-like cavities on the edges of silicon structures.

Virtual fabrication is a more productive way to build integrated MEMS/CMOS systems than process simulation.

by:Maurice J.A. Delafosse is MEMS product engineer, DPFS department, at Dalsa Corp. in Bromont, Canada. 

Gerold Schröpfer is director of European operations and foundry partner program for Coventor in Sarl Paris, France. 

Dalsa Semiconductor and Coventor have published an article on the use of virtual fabrication for MEMS processing. Virtual fabrication process emulation backed up by experimental calibration is a more productive way to build integrated MEMS and CMOS systems than process simulation. It provides a link between fab and design, is a lower-cost and faster technique, and provides a unique method to understand and improve design and process interaction, and wafer control/inspection. It leverages the enormous knowledge and tooling that has been developed in CMOS semiconductor fabrication, and transfers that knowledge to the MEMS world. --> read more

(left) SEM image and (right) SEMulator3D image of process steps in the Dalsa MEMS process.

X-Fab and Coventor present paper at SemiconWest on MEMS fabrication

3-D Process Modeling - A Novel and Efficient Tool for MEMS Foundry Design Support.
We describe a software tool for creating highly realistic, 3-D virtual prototypes of MEMS and semiconductor devices, and show how it has been applied to a MEMS SOI micromachining process. Two case studies demonstrate the value of virtual prototypes to a foundry: a 3-D design rule check that revealed a design error before mask tape out, and a process integration analysis that confirmed the suspected cause of a process failure.

Download presentation

Process emulation techniques are a great way to get 3D models and they are faster to build than simulated models.

Geometric emulation of MEMS Technology. This approach utilizes a geometric description of the result of each process step that is concatenated to build a geometric model of teh complete MEMS device. The geometric emulation approach has become a widely accepted approach for MEMS visualization applications. Koppelman first utilized geometric emulation in the OYSTER program, which was subsequently extended to the MEMBuilder and MEMulator modules incorporated into the CoventorWare software. The geometric emulation approach is capable of modeling the spectrum of process steps (i.e., conformal depositions, planarization, etch profiles, gap fills, etc.) encountered in MEMS processes in a computatially efficient manner, thus providing the MEMS designer with meaningful information.
Micro Electro Mechanical System Design by James Allen. CRC press, Taylor and Francis. page 185.

 

 

 

MEMS Design Validation before Fabrication; X-Fab comments on success

"We have found that SEMulator3D builds 3-D models faster and with greater accuracy than conventional TCAD process simulations, and these models are obviously much more accurate than manual drawings of 3-D structures or 2D cross-sections. The benefits of visualizing accurate 3-D virtual MEMS prototypes include increased probability of achieving first-time success by minimizing analysis errors, increased design efficiency by identifying process errors early, avoiding undesired effects that would have reduced yield, and more efficient communication between design engineers and outside groups."
-- X-Fab Semiconductor Foundries

Publish 3-D MEMS and Semiconductor device models in Acrobat 3-D pdf files

Process Documentation made easy.

Are you tired of manually drawing process flow cross-sections? Tired of drawing sketches of devices for presentations?

There is a better way to transfer process knowledge, communicate about engineering decisions and create valuable presentations. With SEMulator3D you can automatically create cross-sections in full 3D, automatically create process flow presentations and even create process animations and interactive 3D content for PDF documents.

With SEMulator3D you can export your 3D Device and Process models right into Adobe Acrobat 9 Pro Extended.
Click on the image to download a sample Adobe Reader PDF file with a 3D model of a Digital Mirror Device.(File size = 1.5 MB)

SEMulator3D 2008.100: New Selective Wet Etch and MEMS Lift-Off capabilities

SEMulator3D 2008.100 enables more realistic wet etch emulation and MEMS lift-off.

Wet isotropic etch steps are commonly used in both Semiconductor and MEMS process flows. Wet etches are usually etch both laterally and vertically (ie, are isotropic) and etch different materials at different rates. The new "Selective Conformal Etch" capability realistically emulates wet etches by allowing the user to control both the vertical/lateral etch rates and individual material etch rates.

In MEMS technology, release etch steps commonly cause pieces of material to become detached from the wafer. These small pieces are usually flushed away by the etchant. A new "Lift-Off" function in SEMulator3D 2008.100 identifies separated pieces of material and removes them from the wafer.

Visit the SEMulator3D Download Center or contact your Coventor support representative for details about how to upgrade to SEMulator3D 2008.100.