Lec_25 - Professor N Cheung, U.C. Berkeley Lecture 25 EE143...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 1 Capacitive sensors Typically used to measure displacement C ~= e A/d Separation (d) Area (A) C(x)=C(x(P)) Example: Pressure Transducer Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 2 CO Microsensor Process Flow Source: http://www.itri.org.tw/mems/ Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 MEMS Mechanical Switch Drain Source Gate(s) Contact Areas: 0.4x0.4 um 2 to 8x8 um 2 Devices from 50 um to 250 um long Drain Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 Mechanical Switch Process Flow Isolation Elec0 Layer Si Substrate Dimple hole Main Sacrificial (LTO) Pattern Elec0 Pre-alignment Isolation Growth 6000A Low Temp Oxide 1000A Stoichiometric Silicon Nitride Poly 0 Deposition Poly 0 Formation RIE to isolation w/ overetch Main Sacrificial Deposition 5500A Low Temp Oxide Dimple Formation DRIE to Isolation or timed DRIE Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 Fine refill sacrificial (HTO) Anchor holes Elec1 Layer Sacrificial Release Fine Sacrificial Deposition 650A High Temp Oxide Anchor Formation DRIE to isolation layer Poly 1 Deposition 5500A @ 615C n-doped Poly 1 Formation RIE etch to Main Sac Sacrificial Release HF:HCl 20 then critical pt. dry Process Finished Mechanical Switch Process Flow Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 6 (gold) = 14 x 10-6 / o C (Si) = 2.6 x 10-6 / o C Example of Thermal Bimorph Actuator Professor N Cheung, U.C. Berkeley Lecture 25 EE143 F2010 7 0 volts- open 15 volts-closed Process Flow of Micro-tweezers by selective CVD Tungsten Professor...
View Full Document

This note was uploaded on 03/03/2012 for the course EECS 142 taught by Professor Ee142 during the Spring '04 term at University of California, Berkeley.

Page1 / 26

Lec_25 - Professor N Cheung, U.C. Berkeley Lecture 25 EE143...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online