Modeling and tests of the electron shadingeffect in plasma-induced oxide damage

Si substrate

source drain

gate oxide gate

VG

VSVD

channel

The electron shading effect

Hashimoto et al. JJAP 1994

Test structures to measure local potentials & currents

PARTICLE ANALYZER

LEADS

+

--

a

Cross section along dotted line

6” aluminium plate

Holes (vias)

a

a

a

‘a’ :checking uniformity

to scope metal

collectingsurface

Insulating material

Contemplated First try

An ICP is needed to keep KTe high while n is low(to makeD >> trench size)

35.7 cm

Two loopantenna

Pyrex Top1.3 cm thick

30 cm

B-Bot Probe

21 cm

Initial Results

Isat @ 5 mtorr for different bias voltages

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

40 50 60 70 80 90 100

rf power/ Watts

Isat /

mA

C1 (9.5V)

C2 (9.5V)

C1 (135V)

C2 (135V)

0

3

6

0 40 80 120 160 200

RF power/W

Ion cu

rrent

/micr

o-A

d(5)-5mT

d(5)-10mT

d(7.5)-5mT

d(7.5)-10mT

Plasma condition

s

Ne, Te, Vp

Sheath calculations

Ion & electron fluxes

Trajectory tracing

Ions

Current

Satisfies boundary condition

?

END

modified

Potential on

boundary

Electric fields

NO

YES

Boundary recognitio

n

Input guess to Potential

on boundary

Calculation flow chart

Potential lines

-1.300E+01 1.300E+01X

0.000E+00

2.200E+01

Y

File prefix: Help7.EOUPlot type: ContourQuantity: Potential (V)

Minimum value: -6.999E+00Maximum value: 2.000E+01

-4.749E+00 -2.500E+00 -2.500E-01 2.000E+00 4.249E+00 6.499E+00 8.748E+00 1.100E+01 1.325E+01 1.550E+01 1.775E+01 2.000E+01

Current viewwindow

Modeling: ion orbits in given E-field

0 1 10 4 2 10 4 3 10 4 4 10 4 5 10 40

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

0.011

0.012

0.013HS

0

ynb

W0 xnb

0th iteration: Ions collected in sidewall bins (42000 ions, 0->L)

0

5

10

15

20

25

30

4 6 8 10 12 14 16 18 20 22 24 26 28 (col)30

R egion #

Convergence after many iterations

-10

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10

Iteration #

Ions

col

lect

ed