This document describes a single-semester MEMS course that combines design and fabrication. It aims to provide students a holistic MEMS experience. The course uses a simplified quasi-surface micromachining process called UIC SOI that allows students to experience key fabrication steps in one semester. The course is divided into two modules - the first focuses on design and the second on hands-on fabrication. Students design, model, and fabricate a MEMS device as a class project using the UIC SOI process, which involves two mask layers and steps like metal deposition, lithography, and release. Thermal actuators were successfully fabricated as an example project.

1. SINGLE-SEMESTER PROBLEM-ORIENTED MEMS COURSE USING
A SIMPLIFIED QUASI-SURFACE MICROMACHINING FABRICATION
PROCESS (UIC SOI)
1Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607
Educating a new generation of MEMS engineers presents a unique challenge
when it comes to curriculum development [1]. Traditionally, MEMS is taught
by dividing the subject into two distinct modules a) a MEMS design and b)
MEMS fabrication. These two modules often represent two semester-long
courses, where the students are separately introduced to MEMS design,
modeling, and fabrication. Such divided approach may be undesirable based
on two key issues:
A) Year-long Curricular Commitment: A full academic year is required
before the students are fully adept in both the microfabrication and
design and are able to carry out independent MEMS research. This
may be especially problematic for part time or graduate students.
B) Lack of Continuum for Relevant Project: Lack of holistic coverage of
all components of MEMS fabrication cycle prevents students from
conducting a relevant class project. Yet, hands-on project
experience is arguably the most important part of the MEMS class
experience.
In this poster we present the outline of a comprehensive
MEMS/Micromachining class that combines MEMS design and fabrication into
a semester long course aimed at providing the students with a holistic MEMS
educational experience. The presented curricular outline combines lectures
(theory) with laboratory exercises allowing the students to both design and
fabricate a MEMS device of their choice. As part of the curriculum we have
developed a simplified multi-project fabrication process called UIC SOI, which
allows the students to experience all the key components of MEMS fabrication
within a limited, single semester duration. Similar topics are covered at
Stanford University MEMS curriculum [2].
[1] Pruitt, B.L. et al., in Proc. First North American workshop on MEMS Education, 2005.
[2] Barlian, A. in Proc. Solid-State Sensors, Actuators, and Microsystems Workshop, Hilton
Head Island, South Carolina, June 4-8, 2006
In order to achieve the objective of a comprehensive MEMS curriculum
spanning a single semester, the course ECE 449, Microdevices and
Micromachining Technology, taught at the Department of Electrical and
Computer Engineering at the University of Illinois at Chicago (UIC), was
revised to cover both design and fabrication. The resulting course is aimed at
senior undergraduate students or junior graduate students.
UIC ECE 449 : Single Semester
Hands-On MEMS Course
Example Class Project :
UIC SOI Thermal Actuator
Igor Paprotny1, Ratul Majumdar1, Md Tanim Humayun1, Antonio DiVenere2, Seyoung An2,
Shashank Rajoria1, Raghavendran Mohan1, Nasim Farajpour1, Rohan Jain1, and Manan Sheth1
Introduction
The nominal UIC SOI process consists of a 100 nm thick layer of evaporated
chrome/gold (Cr/Au), a 2 - 3 μm thick layer of silicon (the device layer), a 1-5 μm
thick buried oxide (BOX) layer, and a 400 μm thick handle wafer. The wafer is
processed using two mask layers, GOLD and SILICON. The UIC SIO process is
mimicking a surface micromachining process (hence named quasi-surface
micromachining) however circumvents the often time-consuming LPCVD oxide and
polysilicon deposition steps.
UIC SOI : Simplified Quasi-Surface
Micromachining Process
2Nanotechnology Core Facility, University of Illinois at Chicago, Chicago, IL 60607
Conclusion
We present the outline of a semester-long hands-on MEMS design and
fabrication course which enables the students to design, model, and fabricate
functioning MEMS devices within a single semester. The class is oriented around
a semester-long project where the students fabricate a set of MEMS devices
using a quasi-surface micromachining process called UIC SOI. Process
development fosters problem-oriented learning, as students learn to “debug”
the process, learning invaluable cleanroom experience. More information about
the class can be found here: www1.ece.uic.edu/~paprotny/ece449.htm
MEMS Fabrication from a Design Perspective
Introduction
MEMS Layout and Design
MEMS Modeling – Part 1
MEMS Fabrication – Process Development
MEMS Modeling – Part 2
Wrap-Up
MEMS Layout
(Computer Lab)
MEMS
Fabrication
(NCF)
S
E
M
E
S
T
E
R
Module 1
tapeout
UIC SOI
Module 2
Lecture Topics Laboratory Sessions
Electrostatically actuated MEMS tweezer based on hot arm-cold arm thermal
actuation mechanism were fabricated using UIC SOI. Different designs comprising
of varying dimensions of arm, with and without metal layer deposition were
considered during the CAD and Finite Element Method (FEM). Deflection of arms
each design were analysed and compared with theoretical values and results
reported in other published literatures. The end product we were able to actuate
our devices for about 7 μm which is about 30% less than what was predicted using
FEM modelling.
100 μm
100 μm
50 μm
50 μm(f)
(e)
100 μm 100 μm(d)(c)
(b)
(a)
(above) The outline of the semester long ECE 449 course. The course curriculum is divided
into two modules. In Module 1, the instruction focuses on MEMS design. The students learn
the fabrication process from a design perspective, as well as MEMS layout tools and some
modeling. The labs are focusing on layout and mask design. Following the tape-out of the
masks (two layers) for the UIC SOI process, Module 2 focuses again on fabrication, from a
process development perspective. The laboratory sessions are now focused on the fabrication
of the MEMS devices using UIC SOI. Instruction also focuses on additional modeling.
(above - left) Fabricated thermal actuators using
UIC SIO. (a) and (b) Top and orthogonal view of
the fabricated thermal actuator latch. The
displacement (up to 7μm) is visible in panes (c,e)
OFF state and (d,f) ON state, respectively.
2 m
0.5 - 2 m
500 m
Cr/Au (  100 nm)
Device layer
Buried Oxide (BOX)
Handle wafer
Fabrications Steps:
1. Metallization (Cr/Au)
2. Metal lithography (Mask 1)
3. Device layer lithography (Mask 2)
4. Dicing
5. HF release
8 μm
1 μm
(above) Cross-section of a UIC SIO wafer after
the metallization step (step 1)