Telecom MEMS:

Overcoming Challenges to

Acceptance Through Reliability

Dr. James Wylde

29 May 2003

Table of Contents

PTV10G – an example of a MEMS Enabled Product

MEMS Reliability

Conclusions

Q&A Session

PTV/ATV10GAn example of a MEMS enabled product

ConceptThe PTV/ATV 10G combines a 10Gb/s receiver with a MEMS based VOA

in one packageEnables increased density and lower cost to system vendors (density x2,

CR ~300/ch)

MEMS Reliability

Introduction of emergent technology into

existing technology paradigm requires extra

diligence for customer acceptance

Telcordia offers standardized testing program

for telecom components

– Do not address the unique requirements of MEMS

devices

Bookham program expands on Telcordia to

provide real “time to failure” prediction for

customers

MEMS Reliability

d/do = 0.9 Device has failed

-30

-25

-20

-15

-10

-5

0

5

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

Normalized Deflection [d/do]

Att

en

ua

tio

n [

dB

]

10 % Drop in

Deflection

Each board 8 modules 6 chips per module

MEMS Reliability

Each board 8 modules 6 chips per module

14 pin

Butterfly

packages

Thermistor

MEMS

Chips

Course Temp

Control

-10 to 85 oC

Fine Temp

Control

MEMS Chips

Data Acquisition

10 port Switch

Temp

Power

Multimeter

Temp

Power

Video

DAQ +

Machine Vision

Stress BoardTest Station

Performance Measurement

Software

3 0

3 5

4 0

4 5

5 0

5 5

0 10 0 20 0 30 0 40 0

ti m e [hrs ]

Dis

pla

cem

ent

[um

]

(a)

30

35

40

45

50

55

0 1 00 20 0 30 0 40 0

ti m e [hrs ]

Dis

pla

cem

ent

[um

]

(b)

3 0

3 5

4 0

4 5

5 0

5 5

0 1 0 0 20 0 30 0 40 0

ti m e [hrs ]

Dis

pla

cem

ent

[um

]

(c)

30

35

40

45

50

55

0 1 00 20 0 30 0 400

ti m e [hrs ]

Dis

pla

cem

en

t [u

m]

(d)

Device Degradation (Deflection)

67 mW

125 mW95 mW

82 mW

Highly Overstressed Degradation

(Device Resistance)

2000

2050

2100

2150

2200

2250

2300

2350

2400

2450

2500

0 100 200 300 400 500

Time [hours]

Re

sis

tan

ce

[O

hm

]

Time to Failure

y = 6E+66x-30.648

R2 = 0.9602

0

100

200

300

400

500

600

700

800

900

1000

60 80 100 120 140

Power [mW]

Tim

e T

o F

ailu

re [ho

urs

]

Normal

operating

power

Failure Modes

Permanent Deformation (Permanent Bending)

– Abutment causes added stress

– Creep Damage – High Temp + High Stress

Resistance Change = Drop in Deflection

– 1 - Increase in dislocations due to deformation

– 2 - Boron diffusion into thermal oxide

100 % Overstress

400 hours

0

2

4

6

8

10

12

14

16

18

20

60 80 100 120 140

Power [mW]

Tim

e T

o F

ailu

re [Y

EA

RS

]

Ongoing Work

Influenced by a

abutment

-No Abutment

-Predicted with 95%

Confidence after 4000

hours of data

Low Temp Storage

- Only in Canada

Conclusions

MEMS and “small technology” has the potential to

revolutionize communications and many other field

A significant challenge to the widespread acceptance of “small

tech” is the lack of a sound reliability model

The results of this work have shown promise towards enabling

industry to accurately predict the life expectancy of silicon

based micro devices.