Download presentation
Presentation is loading. Please wait.
1
MEMS Fabrication By Thomas Szychowski
2
MEMS overview Micron level mechanical parts
Made from transistor materials and metals Van Der Waals forces Intermolecular bonding Plays an important part in design
3
Fabrication Techniques
Mask Lithography Injection molding Microstereolithography Silicon Surface Micromachining Silicon Bulk Micromachining
4
Mask Lithography Use of photo resist Multiple layers – Multiple steps
Positive Dissolves under light Negative Hardens under light Both get covered with desired material, then photo resist is dissolved by a solvent Multiple layers – Multiple steps
5
Mask Lithography
6
Injection Molding Starts with mask lithography
Metal poured over resist Resist gets dissolved Metal form is left for plastic injection molding
7
Injection Molding
8
Microstereolithography
Similar principal to mask lithography, but for 3D pieces Uses an “active mask” Not a physical mask Utilizes a photo-reactive acrylic resin Each layer image projected through a DMD(digital mirror device) Projected into the resin Uses lenses Resin that is illuminated, Cross-links and hardens Piece is then covered in a hardened layer
9
Microstereolithography
Dimensional capabilities Lateral and Vertical resolution: 10μm Maximum field size: 10.24mm x 7.68mm Structural height: up to 5mm
10
Microstereolithography
11
Microstereolithography
12
Silicon Surface Micromachining
Uses the same process as IC fabrication Needs multiple layers to create structures Cheapest form of Micromachining Similar to lithography Sacrificial material Structural material When sacrificial material is removed, only whole structures are left
13
Silicon Surface Micromachining
14
Silicon Surface Micromachining
15
Silicon Surface Micromachining
16
Silicon Bulk Micromachining
Done with Crystalline silicon Constructed using etch stop planes Chemical process Anisotropic Etching Speed dependent – Directional etch in different crystallographic directions at different rates Slower directions create and etch stop plane
17
Deep Reactive Ion Etching (DRIE)
Uses photo resist and a mask to create structures
18
Sapphire Etching Metal Mask 100µm etch depth .28µm/min etch rate
Chlorine etching
19
Pressure Sensor Etching
Used on silicon Metal mask .81µm etch depth Utilizes Fluorine
20
High-Speed Etching Silicon material 1µm/min etch rate W-Si Mask
21
Whacky Neato Pictures
22
Questions ?
23
References http://home.earthlink.net/~trimmerw/mems/tour.html
“Micromachining for Optical and Optoelectronic Systems”. MING C. WU
Similar presentations
![Fabrication of p-n junction in Si Silicon wafer [1-0-0] Type: N Dopant: P Resistivity: 10-20 Ω-cm Thickness: 505-545 µm.](/15/4784305/big_thumb.jpg "Fabrication of p-n junction in Si Silicon wafer [1-0-0] Type: N Dopant: P Resistivity: 10-20 Ω-cm Thickness: 505-545 µm.>")
