AMMETER I

"" ^"-...

...__ _ _ _ _ _ _ ELECTRON CAGE

^{/ /}

--

-77-

Figure 7

The normalized differential sputtering yield versus

a

for the low-dose solid gallium run of Table 2. The uncertainty in the yields is. 5% which includes the systematic errors discussed in Chapter III. The uncertainty in 0/n is 0.001.

The continuous line is cos^{1• 94}

a.

+

c:=· ^L

o·

^L

s·o g·q v·o c:·o

0131A

8NI~311nds 3AI1Vl3~

Figur e 7

o·o

0

II)

.

0

0

.

II) N

.

0

I")

0

.

~

CL

"

C:<

c t -

w :r:

t -

I")

0

.

I

II) N

.

0 I

00

I")

0

.

I 0

II)

.

0 I

-79- Figure 8

The normalized differential sputtering yield versus

e

for the high-dose solid gallium run of Table 2. The uncertainties are as quoted in the previous figure caption. The continuous line is cos^{1 • 85}

e.

G" 1

o·

¹

a·o

^9·0

v·o z·o 0131A

~NI~311nds 3AI1Vl3~

Figure 8

o·o

0

II)

.

0

CX) I"")

0

.

II) N

.

0

I"")

0

.

...

CL ...

c: ^<:

c l -

w

I

I -

I"")

0

.

I

II) N

.

0 I

CX) I"")

0

.

I 0

II')

0

.

I

-81- Figure 9

The normalized differential sputtering yield versus

a

for the first liquid galliwn run listed in Table 2. The continuous line is cos¹• 96

a.

G" L

o·

^L

a·o

^9·0

v·o

^G·o

013IA

~NI~311nds 3AI1Vl3~

Figure

9

o·o

0 11)

.

0

CX)

n

.

0

11) ('\J

.

0

n

.

0

-

^a_

...

~<

o t -

w

I t - n

.

0 I

11) ('\J

.

0 I

CX)

n

.

0 I 0

11)

.

0 I

-83-

Figure 10

The normalized differential sputtering yield versus

e

for the second liquid gallium run listed in Table 2. Although no sputtering yield could be obtained for this run due to poor Ar+ beam current integration, the angular distribution is

independent of beam current integration during sputtering.

The continuous line is cos¹·~²

e.

G" L

o·

^L

s·o

^9·0

v·o c:·o 013IA

~NI~3llnds 3AI1Vl3~

Figure 10

o·o

0

LI')

0

.

00

I")

0

.

LI') ('\J

.

0

I")

0

.

-

a...

...

c: ^<

0 t -

w

I t -

I")

0

.

I

LI') ('\J

.

0 I

00

I")

0

.

I 0

LI')

0

.

I

-as-

Figure 11

The normalized differential sputtering yield versus

e

for the solid indium run in Table 2. The estimated uncertainty in yields is 5%, .and the uncertainty in 8/ir is 0.001. The

continuous line is cos^1·!li+

e.

G" L

o·

^L

s·o s·o v·o

^G"O

013IA

~NI~3llnds 3AI1Vl3~

Figure 11

o·o

0

l/')

.

0

0

.

l/') (\J

.

0

·n 0

.

-

0...

...

':<

o1-

w

I

I -

n

.

0

I

l/') (\J

.

0

I

CX) n

.

0

I

0

l/')

.

0

I

-87- Figure 12

The normalized differential sputtering yield versus 8 for the liquid indium run in Table 2. The uncertainties are the same as in the previous figure caption. The continuous line is cos.² • 11.0.

a.

G" l

o·

^L

s·o g·o. v·o

^G"O

013IA

~NI~3llndS 3AI1Vl3~

Figure 12

o·o

0

Lf)

I"')

0

.

-

^Q_

...

c:

^<:

c t -

w :c

....__

I"')

0

.

I

Lf) N

.

0 I

CX>

I"')

0

.

I 0

Lf)

.

0 I

-a9-

Figure 13

Rutherford backscattering spectrum of a graphite foil which collected sputtered atoms from a liquid gallium-indium eutectic target. The Rutherford cross section for indium is 2.5 times as large as the cross section for gallium. The incident ¹

9?

²+ energy was 5.00 MeV.

c-···

.... ^{. . .} . ...

... ··- · ....

^{• ••}

_·.

^I.

-

^IO

^.

~

..

^{:. N}

•••••

":{

·~:Jo·

_{.. .,,} ,,

^...

~~~

•t'

q

-·~· N '~1 _·~

..

^~

. \1''

0 •t.~·,

(!) ~. ·.,)t•

.

, ·::

...

)~;-

, ....

~

-

. . t .,.

· .. 't

.. .

··~

!·(.:

l ::-~

' \ 0

\:;: _Y.·,'

..

_-

^.

.:

~·

f

...

. ·<:

. .

.

~;· ^"

^-

^IO

^.

·,:j 0

~

•.:

,.·•. .,, r··

. · .·

~~~~~~·~~~~~-1.'~~~~~-L·~~---.L...·----~~~'

⁰

IO 0 IO q IO 0

C\i '-'i - d

Figure

13

- _>

:e

cu

- >-

<!)

a:

L&J

z

L&J

-91- Figure 14

The normalized differential sputtering yield versus

e

for galliwn sputtered from a liquid_ gallium-indiwn eutectic target by 15 k.eV Ar+. The target temperature was 31.8°C

(see Table 3}. The continuous line is cos^{3• 7}

e.

Compare the angular distribution to the indiwn distribution taken from the same target in Figure 15.

+

c::·

^L

o·

^L

s·o s·o v·o z·o 013IA

~NI~3llnds 3AI1Vl3~

Figure 14

o·o

0 10

.

0

I"")

0

.

-

a_

...

':<

o l - -

:c w

I--

I"")

0

.

I

10 N

.

0 I

CX) I"") 0

.

I 0 10

.

0 I

-93- Figure 15

The normalized differential sputtering yield versus

e

for indium sputtered from the same liquid eutectic target as in Figure 14. The incident sputtering beam was 15 keV Ar+.

The continuous line is cos¹• 99

e.

+ +

+

l" l

o·

^t

s·o g·o v·o i·o

013IA

~NI~3llndS 3AI1Vl3~

Figure

15

o·o

0 LO

.

0

00

!"')

.

0

LO

(\J

.

0

!"')

0

.

...

a...

...

~<

o l -

w

:J:

I -

!"')

0

.

I

LO

(\J

.

0 I

00

!"'")

0

.

I 0 LO

.

0 I

-95- Figure 16

The normalized differential sputtering yield versus

e

for gallium sputtered from a liquid gallium-indium eutectic target by 25 keV Ar+ (see Table 3}. The continuous line is cos²·n

e.

+

z·

¹

o·

¹

s·o

^9·0

v·o z·o

013IA

DNI~3110dS 3AI1Vl3~

Figure 16

o·o

0

II)

.

0

CX>

n

.

0

II) ('\J

.

0

n

.

0

- ^a...

...

C:<

ot--

w

I

1--

n

.

0 I

II) ('\J

.

0 I

CX>

n

.

0 I 0

II)

.

0 I

-97- Figure 17

The normalized differential sputtering yield versus

e

for indium sputtered from the same liquid eutectic target and by the same 25 keV Ar+ beam as in the previous figure. The continuous line i$ cos¹ •~⁸

e.

z·

^L

o·

^L

s·o g·o v·o z·o 0131A

~NI~311nds 3AI1Vl3~

Figur e 17

o·o

0

"' .

0

00 I")

.

0

"'

^N

.

0

I")

0

.

t--4

CL

...

c: ^{< .}

o t -

w :r:

I -

I")

0

.

I

"'

N

.

0 I

00 I")

0

.

I 0

"' .

0 I

-99- Figure 18

Rutherford backscattering spectrum of a graphite foil which collected sputtered atoms from the first run on the quickly frozen eutectic target. The total accumulated Ar+

at the end of the run was 3.33 mCoulombs (see Table 4).

The energy of the incident ^l!lF2+ beam was 5.00 MeV.

....

c

-·- ^{-·· . ·- . . . .}

I I

in 0 in

N N

-

i+ .:161

. .. _{. ...}

I

q

::>r11 S.lNno::>

Figure

18

I in

0

- q _f")

.. ...

0 0

- _>

_Q)

-

::E

-101-

Figure 19

Rutherford backscattering spectrum of a graphite foil which collected sputtered atoms from the second run on the quickly frozen eutectic target. The total accumulated Ar+

at the end of the run was 8.33 mcoulombs (see Table 4).

~---..;. 0

....

c

-. ^{.. · .}

^;.

^{· ... . .} . ^..

·~·"

^{. ..}

..

. rti 0

\

. . .

_{. t .}

..

'· _{.. ...}

.

^.) _··~N

..

^-~

.•tc

....

!:i

··I

, ,,1

'

•

·J t 0

'N I

. .i .

.

^•.:

. ....

^{•• , r}

a , .. ·

o - · . .

^{• 1.: \ .}

^{, . . .} .

^,

~---~·~---~·~---~·~---~·!:---:0

in 0 in

q

ⁱⁿ 0

C\i N

o

Fi gure 19

-

- >-

<!>

a::

I.LI

z

I.LI

-103-

Figure 20

Rutherford backscattering spectrum of a graphite foil which collected sputtered atoms from the third run on the quickly frozen eutectic target. The total accumulated Ar+

at the end of the run was 13.3 mCoulombs (see Table 4).

.;

I _in

~ _~

.f

: .i q

-=

,.,.,

.

c: _ .: ... .

.. . . .. ..

^~·

~

.... . ..

_'

.

a _

C>

...

.... ^{. . . .}

..

^~

. .. . _{. .}

_,.

2 + .:161 :) rt I

S.lN no:)

Figure 20

...

. · ...

1

q ~

·: N C>

.· .l ^a::

^L&J

L&J

z

-105- Figure 21

The composition of the material sputtered from the solid gallium-indium eutectic versus incident Ar+ dose. The shaded blocks represent sputtering runs of the quickly frozen target while the unshaded blocks represent the target which was

frozen gradually.

0 0

I

^I

0

m

!.•

I·

I•

I•

,,, . l•

I

0 <X>

I

0

,.._

, .

0 <D

I 0 I{)

. I

0 v

Figure 21

I

0

,.,.,

I

I I I I

c:

I

~I - _~I

!I .51

I I I

I I

I '

L•

I

I·

I

ii

I

I•·

I

'!

I

h·. I

I

l

·,

I

I

•

^I

0 N

. · ..

I

0

-

-

-

-

-

· -

-

· -

-

-

N N

0 N

<X>

<D

v

N

0

<X>

<D

v

N

0 0

- _"'

.0

E

0

~

0 (.)

- E

+ ' -

c::x:

I-

z w

0

(.)

z

LL 0

w en

0 0

-107- Figure 22

The normalized differential sputtering yield versus 6 for indium sputtered from the slowly frozen eutectic target during the first run listed in Table 4. The total accumulated Ar+ at the end of the run was 11.0 mCoulombs. The continuous

line is cos¹ • 41

e.

+ +

c:·

¹

o·

¹

s·o

^9·0

v·o c: · o

0131A

DNI~3llnds 3AI1Vl3~

Figure 22

o·o

0

1f)

.

0

0

.

1f) (\J

0

I")

0

.

...

0....

...

C:<

o l -

w

I

I -

I")

0

.

I

1f) (\J

.

0 I

co I")

0

.

I 0

LI)

.

0 I

-109- Figure 23

The normalized differential sputtering yield versus

e

for indium sputtered f.rom the slowly frozen eutectic target during the second run listed in Table 4. The total accumulated Ar+ at the end of the run was 21.·o mCoulombs. The continuous line is ^COSQ.~2 8.

+

z·

^L

o·

^L

s·o

^9·0

v·o z·o

013IA ~NI~3lln~s 3AllV13~

Figur e 23

o·o

Lt)

.

0

0

.

Lt) N

.

0

n

.

0

- ^a...

...

c::

^<:

a t - -

w

I I--

n

.

0 I

Lt) N

.

0 I

(X) n

.

0 I 0

Lt)

.

0 I

-111-

Figure 24

The normalized differential sputtering yield versus

e

for indium sputtered during the first run of the quickly frozen eutectic target. The total accumulated Ar+ at the end of the run was 3.33 mcoulombs. The continuous line is cos¹• 6

e.

+

z.

^{l 0. l}

s·o

^9"0

t·o z·o

013IA

8NI~311ndS 3J\Il\f'l3~

Figure

24

o·o

0

It)

.

0

0

.

It)

N

.

0

n

.

0

.-

Cl...

...

~<:

o~

w

I

~

n

.

0 I

It) N

.

0 I

n 00

.

0 I 0

It)

.

0 I

-113- Figure 25

The normalized differential sputtering yield versus

e

for indium sputtered during the second run of the quickly frozen eutectic target. The total accumulated Ar+ at the end of the run was 8.33 mCoulombs. The continuous line is cos¹ • 3

e.

+

G" l

o·

^L

s·o

^9·0

v·o

^G"O

013IA

~NI~3llnqS 3AI!Vl3~

Figure 25'

o·o

0

It)

.

0

CX>

n

.

0

It) ('\J

.

0

n

.

0

-

^a_

...

~<

o~

w

I

~

n

.

0 I

It) ('\J

.

0 I

CX>

n

.

0 I 0

It)

.

0 I

-115- Figure 26

The normalized differential sputtering yield versus

a

for indium sputtered during the third run of the quickly frozen eutectic target. The total accumulated Ar+ at the end of the run was 13 •· 3 mCoulombs. The continuous line is cos¹ •2

a.

+

G" L

o·

^L

s·o

^9·0

v·o

^G"O

013IA

~NI~3llndS 3AI1Vl3~

Figure 26

o·o

0

Lt)

.

0

0

.

Lt)

N

.

0

n

.

0

-

^Cl... ...

':<

o l -

w

I

I -

n

.

0 I

Lt)

N

.

0 I

CX>

n

.

0 I 0

Lt)

.

0 I

-117-

Figure 27

Photograph of the ion scattering spectroscopy apparatus which was inserted between the analyzing magnet and the target

chamber.

Figure 27

-119- Figure 28

ISS spectrum of a pure solid gallium surface. Each point represents the number of particles detected per 10-⁷ Coulomb of incident 2 keV Ar+ on target. The detected particles can be sputtered ions as well as scattered Ar+.

The peak labeled gall.ium is comprised of Ar+ ions which were scattered from gallium atoms on the surface.

. . . . · ... ..

( ! ) - · D

. . . .. . ... . ^,

:'~ ..

·:~ ^·"

.~· !.'··

.

^~.

~~ \X.·

: • (t,•

_g

0 N

~ ~·

-~~ 0

-~ - ~

.i. ...

~=; ^~

•f\·

.:i:. =~.

=~~·

:'i . ... : t;:·

^,

··~·:

. .. ^{.. ,·,:·.}

• :f,t::.r.-

·.

t. ... ^._

-· .

•,I,_\•: • ._

·.

.• ii ... _...

_, ·J'. " . · ..

·=·~

^· \• .

• "L"• • : • ( l" •

'·· ..

. . . . .... .

^·~

_:

^•_.

·. .

^~ _ff.I.

.... .

• .-: • ·' • ^·:

- ^...

^·~

. \ -~ t.·. .

·.!·~.. .~

.: ..

.

^:

^_ ...

^::

.

. . . .

^,

. .. . . . . .

. .

_9\

. .

_{•• •}

^·.·: ..

_•

.

.:·:.1.~.

. . ^..

^,

^{.. . .}

.,

^{·.:~ ~}

. .

-g

0

-o 0 _I()

, _ _ _ _ _ _ _ _ _ _ _ _ _ _ , , , _ _ _ _ _ _ _ _ _ _ _ _ . . , . , _ _ _ _ _ _ _ _ _ _ _ _ _ ...._1 _ _ _ _ _ _ _ _ _ _ _ _ L - 1 _ _ _ _ _ _ _ _ _ _ ~0

~

8

~

8

~ ⁰

N N

S.LNno:> .:fO ~38WnN

Figure 28

- >

_Q)

-

_<.!)

>- a:

L&J

z

L&J

-121- Figure 29

ISS spectrum of a pure solid indium surface. Once again, the counts can represent sputtered ions as well as scattered Ar+. The peak labeled indium is comprised of Ar+ ions which were scattered from indium atoms on the surf ace.

.. . . .

....

c

.. . .

. >~'! .

..

'

-·

^~'

^{. .}

^'

^{. .. . - .. . ..}

^~

^..

···~·.

. ·-:i.:'. ...

^'

..

""

::;

.,,

..

.. ^{•:-.:-· .}

·--·~·

. :. i:.

•-:."Ji. .

••• •• it ~

• _,,, e

_.,I

_{.. i}

. •. a.;., •.. · ... _. ., ^,,,. ·-· ^··

:.~·-.;

: ;..·:··;

, . ..

_{1 1 J I}

. • . •.. . ·

• • ·~ r ·.,

..

^'.:

· ^...

:

:.

. . _. ... .

'

.

^{., ·:·}

^, .

.. ^.

^'

^..

-

-

-

0

8

N

0 0

IO

0 0

2

- C> 0

IO

• • I \

... ~~~-'~~~ ... ·~~~~~~-... ·~~~~~~--'·'--~~~~~~ ... ·~~~~~~___,C>

~ ~

8

~ ⁰

S.lNno:> .:10 ~:38WnN

Figure 29

- >

_Cl>

-

~

<.:>

a:

w z w

-123-

Figure 30

ISS spectrum of the liquid_ gallium-indium eutectic alloy.

A previous sputter-cleaning exposed some of the tantalum on which the liquid alloy was supported.

....

c

-· ^{. . .... ....}

^:•

^.

.. ;l:· - -~f

:, ~-·

•• -,'! •

-.;.'(:

ii-.:. .

. :.,:.-

.

,"J: ..

-" .

.... s.:.: •

,rf .

^:.·

• ·t':.'f·

... --~

~<7·

.

_,~, ^,,,

_. -

.:)1.-

. _.. .. ,, _. ^...

_··~

. . l:(

a . .,.,

a.=.~·?' ^:Ii.

r- -~ .

.. _.

^:':~

~--=

. _.,-:; ..

^..,

..

_: ^:

. _... ....

. , . . · .. -· _-

.. . ... .... _-. ^. _{. -:.}

.... . ...r •• _. '· _··~

_.;

... -·

.~~~·

.r.. : . .

:::a.

:,r.,, •

. . .

^·~--

· .. ·: .. . . . .

^;,,.:,:,

..

. ^"• ·"' . .

^{;.· ·:·}

.. · .

• • #

... >' .

• r :·

•4'? • • • . . . · l •

.. t·.,· .. ,,.

..

^1·~·

.... ·r.:! • ••

. . ^"' .

. . .. : .•..

^:

. . .

^{' .,.}

. . ^..

_f

, ....

_{4 • •}

-

. . . • #

. ... : ...

^~

...

. . . _{. ·.}

^'

_,.- . .. _... . .

; (

..

^"

_{. ..} .

^·~

. . .

^:-

.... .. . .

_{• • • I}

·:--

§ -

8

It)

~~~~~~.._•~~~~~~·~~~~~

...

·~~~~~__,o

8 ~ 8 ~

⁰

N

Sl.NnO~

.:10

~38

wnN

Figure 30

- _~

- >

(!)

a:::

Lii

z

l&J

-125- Figure 31

Schematic diagram of the ISS apparatus. The incident beam trajectory is perpendicular to the plane of the diagram.

UHV CHAMBER 121• ELECTROSTATIC ANALYZER

i

.,

____ ..., _ _ _ ... .__ -

l,

- - - - -I

---

...- __ _

...

___ _

.. ~ ^... ---

\.-~ / ...-

">/

MACOR

CHANNELTRON HOLDER

I I I I I

,1

I \

^I I

Fi

¹¹

I

I

\:;~-:b.rJ

¹¹

BENDIX CEM (~ I

I

4039 CHANNELTRON _ _ _ _

ll

^{_!il ___ ~ I Q}

I

VERTICAL ION BEAM

Figure 31

II ~1:±-.J.=~ =4=~

¹¹

IL----...ll

,._,J ~ ..

PORT FOR ELECTRICAL

1

FEEOTHROUGHS

-127-

Figure 32

Photograph corresponding to the point of view taken in the schematic in Figure 31. Part of the electrostatic analyzer can be seen through the viewport.

Figure 32

-129- Figure 33

Schematic diagram of the multichannel scaling arrangement used to collect I.SS energy spectra.

BEAM CURRENT ON TARGET

I

CURRENT DIGITIZER

I

external clock

ND 2400 x-axis display DISPLAY MUL Tl CHANNEL

MODULE ANALYZER

multi scale pulses

LOW-LEVEL DISCRIMINATOR HIGH-VOLTAGE AMPLIFIER PULSE AMPLIFIER

CHARGE-SENSITIVE PREAMP

ELECTROSTATIC CHANNEL TRON DETECTOR ANALYZER

•

I

I

^I

L---...1

analyzed Ar• ions

Figure

33

-131-

Figure 34

Circuit diagram of the amplifier used to provide the voltages for the electrostatic analyzer. This amplifier is referred to as "high-voltage¹¹ in the schematic in Figure 33 to distinguish i t from the amplifier used to amplify and shape the pulses from the channeltron detector.