Answered step by step
Verified Expert Solution
Link Copied!

Question

1 Approved Answer

I only need the second question. Thank you. 8. (25) (Bulk Microfabrication, MEMS capacitor design) The electronic connection routing of a capacitive accelerometer is illustrated

image text in transcribed

I only need the second question. Thank you.

8. (25) (Bulk Microfabrication, MEMS capacitor design) The electronic connection routing of a capacitive accelerometer is illustrated in the following figure, and a 3D arrangement of part of the sending comb drives is drawn to show the structure details. The device is fabricated using silicon substrate. Deep reactive ion etching (DRIE) method is used in creating the structure. All the neighboring electrodes have a same gap of g between them (after fabrication processes). The electrodes with the same color are connected to form one electrode. Assume that the highest aspect ratio (depth/width) the DRIE system can achieve is 30. In real etching, an anisotropic silicon etch rate of 2 um/min (along the depth direction) and a simultaneous undercut rate of 10 nm/min are also assumed. Understand the connection of the electrodes and how the comb drives are formed. 1) If the engaged length of the capacitor comb finger L = 100 um, the mask photoresist has a gap of go = 2 um. For a maximum final comb gap g=2.5 um, what is the largest capacitance of this group of comb drives? 2) What comb drive thickness should you design? (Neglect the effect of scallops, assume the sidewall is straight). 3) Describe how the DRIE process works in creating high aspect ratio structures like the comb drives in the figure. Anchor Spring +V. Proof Mass -Rotor fingers + Stator fingers V. Illustrative sensor connection Vo +Vw 9. II-Etching mask - PR g H Rotor Stator fingers fingers Comb drive structures and etching profiles 8. (25) (Bulk Microfabrication, MEMS capacitor design) The electronic connection routing of a capacitive accelerometer is illustrated in the following figure, and a 3D arrangement of part of the sending comb drives is drawn to show the structure details. The device is fabricated using silicon substrate. Deep reactive ion etching (DRIE) method is used in creating the structure. All the neighboring electrodes have a same gap of g between them (after fabrication processes). The electrodes with the same color are connected to form one electrode. Assume that the highest aspect ratio (depth/width) the DRIE system can achieve is 30. In real etching, an anisotropic silicon etch rate of 2 um/min (along the depth direction) and a simultaneous undercut rate of 10 nm/min are also assumed. Understand the connection of the electrodes and how the comb drives are formed. 1) If the engaged length of the capacitor comb finger L = 100 um, the mask photoresist has a gap of go = 2 um. For a maximum final comb gap g=2.5 um, what is the largest capacitance of this group of comb drives? 2) What comb drive thickness should you design? (Neglect the effect of scallops, assume the sidewall is straight). 3) Describe how the DRIE process works in creating high aspect ratio structures like the comb drives in the figure. Anchor Spring +V. Proof Mass -Rotor fingers + Stator fingers V. Illustrative sensor connection Vo +Vw 9. II-Etching mask - PR g H Rotor Stator fingers fingers Comb drive structures and etching profiles

Step by Step Solution

There are 3 Steps involved in it

Step: 1

blur-text-image

Get Instant Access to Expert-Tailored Solutions

See step-by-step solutions with expert insights and AI powered tools for academic success

Step: 2

blur-text-image

Step: 3

blur-text-image

Ace Your Homework with AI

Get the answers you need in no time with our AI-driven, step-by-step assistance

Get Started

Recommended Textbook for

Handbook Of Energy Audits

Authors: Albert Thumann, Terry Niehus, William J. Younger

7th Edition

1420067915, 978-1420067910

More Books

Students also viewed these Accounting questions