Transcript Parylene Tutorial

Outline
 Parylene Properties
 Deposition of Parylene
 Parylene Etching
Properties of Parylene
 Parylene, a white granular powder, is a generic name for a class of polymers called
Poly-Para-Xylylene.
 Parylene material was discovered by M. M. Swarc in 1947 and it was
commercialized by W. F. Gorham in 1965.
 Based on how the aromatic or aliphatic hydrogen atoms are replaced with other
atoms or chemical groups, parylene is classified into 20 types
 However, only 4 of them are widely in parylene N, C, D and F
Parylene-N
Parylene-C
Parylene-D
Parylene-F
Properties of Parylene
 Parylene does not produce any out-gassing, and has low permeability to
moisture and gases.
 Deposited at room temperature
 Compatible with silicon micromachining
 As deposited it is hydrophobic (water contact angle of ~98)
 But can be made hydrophilic with a short plasma treatment (ca ~ 10 )
 It has high tensile strength (10,000psi) and high mechanical strength
(Young’s modulus of 400Kpsi)
Parylene Deposition
Three stage vapor deposition process
PDS 2010
Parylene Deposition
Dep. Rate=0.5um/gram
Deposition rate of parylene C
Parylene Etching
- Low Temperature, low pressure and High Aspect Ratio
(HAR) Parylene etching using Inductively Coupled
Plasma (ICP) is developed
- High Aspect Ratio > 8:1
- Etching Recipes
Etch#
Etch Rate
(µm/min)
RF Bias
power(W)
Source
power(W)
O2(sccm)
Ar(sccm)
a
1.7
250
400
20
0
b
1.0
100
400
10
10
c
0.5
100
150
10
10
Scanning Electron Micrographs of
etched Parylene structures
A
B
Anisotropic profiles of (a) 55 µm and (b) 10 µm thick parylene
Scanning Electron Micrographs of etched
Parylene structures
Scanning Electron Micrographs of etched Parylene
structures
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