1. Surface Micromachining
מיקרועיבוד - משטחי

2. Introduction
* A Short Preview
FlowDesigner Surface
Pressure Sensor

3. Fabrication Steps Details
Pattern Transfer to SiO2
Buffer/Isolation Layer

4. Fabrication Steps Details
Sacrificial Layer Deposition and Etching

5. Fabrication Steps Details Cont.
Deposition of Structural Material
* LPCVD of PolySi (25 to 150 Pa), 600 deg C
* Also: Thermal Oxide, Si3Ni4
Selective Etching of Sacrificial Layer

6. Fabrication Steps Details Cont.
Etchant – Spacer – Microstructure Combinations

7. MUMPs –Multi User MEMS Project A commercial fabrication process
MCNC – CRONOS – JDSU - MEMSCAP
MEMSCAP - MUMPS
MUMPs Design Rules

8. Stiction * Stiction During Release
Stiction After Release : In-Use Stiction –
A fundamental reliability issue!

9. Mechanical Properties of Thin Films
Adhesion

10. Mechanical Properties of Thin Films Cont.
Stress in thin films
Thermal stress

11. Mechanical Properties of Thin Films Cont.
Stress Measuring Techniques
T – Substrate thickness
E – Substrate Young’ Modulus
R – Radius of curvature
t - Film thickness
 - Poison ratio
* Disk Method – Stoney Equation:
* Uniaxial Measurements

12. Surface Micromachined Structures to Gauge Intrinsic Stress
* Clamped Clamped Beams
* Ring Crossbar Structures

13. * Vernier Gauges LS – Slope Beam Length Li – Indicator Beam Length
Lt – Test Beam Length
C – Correction Factor
* Vernier Gauges

14. Cantilever Beams

15. Control of Film Stress

16. Test Structures – Microstructures Analysis Through Fabrication
ISRAMEMS
2003