SCIENTIFIC ABSTRACT SNITKO, O.V. - SNITSARENKO, L.G.

• Document Type: CREST
• Collection: Scientific Abstracts
• Document Number (FOIA) /ESDN (CREST): CIA-RDP86-00513R001651810015-3
• Release Decision: RIF
• Original Classification: S
• Document Page Count: 100
• Document Creation Date: November 2, 2016
• Document Release Date: August 26, 2000
• Sequence Number: 15
• Publication Date: December 31, 1967
• Content Type: SCIENTIFIC ABSTRACT

27948
S/185/60/005/004/007/021
Effect of the external electric... D274/D306
for a sinole surface state only. As the- germanium and silicon
surfaces have 4 frist st.-ites, it is of i-aterest to generalize John-
Soli's formula for any nLI(Rl)cr of states. Vs is determined from
vs y @z- W dY
p e e dAp (2)
where 6. i@ the relative increase in hole-concentration during
ations one ob
illum, ination of the specimen. @@fter some traisform-
t ai ns ), -Y
dY ?.@e +e -2
d A
p + V (Ij
where
=@+I npit Tj >> I
-X2 npll Tj< 1 (12)
I + e-'Y-ln x+'j)1-2e- (1*-")'+Y.
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27941*) S/185/60/005/004/007/021
i@fEect of tile external electric ... 1)274/D306
Formulas (2) and (11) determine the dependence of the photo-cmf
V.S on the sijrf@ice potential and surface states. gigures are shown
w1th theoretical and experir,'iental curves Vs(Y). It is noted that
p
the agreement bett..reen theory and experiment is good qualitatiVely
only, whereas quantitatively there are discrepancies; these may
be due to neglecting slow surface states, arid to errors in deter-
atining the surfac potential and s
urface states. Further, the
dro-@) is consic1cred in the capacitor photo-emE vhich depends on ZS.,
For silicon, the time constants '),' p arid -C are not only-of diff-
erent magnitude (in the absence of an external field), but tlicir
depc-ndence on Y is of a different character too. It is likely
that the -@`orriation of a D-n junction at the silicon. surf ace hin-
ders the relaxation of the Dhoto-emf. The i:iagnitude of 'r is
P . The
determined by diffusion processes and surface recombination
surface conditions (zone bucklinor and surf ace states) have a con-
siderable effect on the photo-emf of silicon and -rcrmanium. The
surface potential Y can be determined in principle by compariug
experimental and theoretical values of V pM and V p(Y). But such
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2
/18 51601005/0 /0 0 7/0 2 1
Ef Ilect (,f the external cLectric D274/D306
OR)
Instvtlit lizyl,:y A' Ul'Si-,, (PhVsics Institute z@,S Ukrs"
',;o-,-7e7..bcr 5, 1959
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89270
S/1 21/61/003/OD1/002/OZ'T2
B1 02/B21 2
f 4/30 0
AUTHORS: Primachenko, V. Ye. and Snitko, 0. V.
TITLE: The role of a dielectric in investigations of the field
effect in semiconductors
PERIODICAL: Fizika tverdogo tela, v. 3, no. 1, 1961, 15-18
TEXT: One of the most important methods used to study the surface
properties of semiconductors is the method of the field effect (change of
the surface conductivity under the influence of an external electric field@
here the semiconductor is a capacitor plate which is covered with a di-
elec;ric (mica, strontium titanate) to increase the breakdown voltage.
Therefore it is of interest to know the effect of the dielectric on the
surface properties of the semiconductor; several studies made for this
purpose (among others, by Shao and Morrison) are briefly discussed in the
introduction. In the following, the authors report on their own experi-
ments. First, they repeated the experiments of Shao and found that a
considerable charge remains on the mica after the electrode has been
removed iinter voltage. Then,experiments have been undertaken to measure
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89270
S11 81/61/OD3/001/002/042
The role of a dielectric in... B102/B212
the field effect and the capacitor photo-e.m.f. directly, with and without
mica, in a vacuum and in air. These experiments were made with n- and
p-type Ge and n-type Si. As the results obtained were similar, only those
concerning the n-type Ge (1.- 28 ohm-cm, thickness 340 @L) are discussed.
Fig. 1 shows the change of the conductivity AT and the capacitor
photo-e.m.f. V , measured for 15 seconds after a constant field had been
applied, as a @unction of the capacitor charge (Q=CV); C with mica has
25 p+LF, without mica, 10.5 ppF. Fig. 2 illustrates the long-period
relaxation effect of the field for various cases. It is demonstrated
again that curves recorded with and without mica coincide in dry air and
in a vacuum, while those recorded in humid air deviate considerably from
each other. Relaxation is more rapid wit mica. All experiments showed
consistently that in fields up to I- 2-10@ v/cm, no charges are transferred
from the semiconductor to the dielectric in dry air and in vacuo. Results
obtained for humid air are indicative of a partial charge transfer to mica,
which increases with humidity; this is related to the surface conductivity
of mica in humid air. There are 2 figures and 9 references: 6 Soviet-bloc
and 3 non-Soviet-bloc.
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SNITKO" 0. kwid.fiz.-matem.nauk
, I I
-------- - -
SemiconductorS. Nauka i zhyttia 11 no-3:25-27 Rr 162.
(MIRA 15.8)
(Semiconductors)

S/181/62/004/010/045/063
B102/B112
AUTHORS: Primachenko, V. Ye., Litovchenko, V. G., Lyashenko, V. I.,
and Snitko, 0. V.
--Vty carrier adhesion on.the silic'bn surface
TITLE: Minor
PERIODICAL: Fizika tverdogo tel4, V. 4, no. 10, 1962, 2925-2930
0
TEXT: This paper is aimed to show that under certain conditions a
charge accumulation may occur on the silicon surface and that the
bipolarity (,@In - 6p) may be disturbed. This is, however, contradictory
to the observations made by other authors (see e.g. Phys.Rev.101, 1272,
1956; Semic.Surf.Phys.,85,1957). The disturbance of bipolarity of the
intrinsic photoconductivity observed is attrAu 'ted to minority carriers
accumulating on fast surface levels. The same method of investigation
was used as described in previous papers (FTT 1,980,1959; FTT 2, 5911
1960; UFZh,5,345,1960). The specimens were n-type Si single crystal
platelets 200-400g thick with resistivities of 30 - 200 ohm-cm and volume
lifetimes of - 1000gsec, the surfaces of which had been etched with CP-8.
in germanium the bipolarity-o@f the surface photocurrent may be disturbed
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S/181/62/004/010/045/063
Minority carrier adhesion on ... B102/B112
only at low temperatures, but in etched silicon it may be disturbed even
at room temperature. This is proved (1) by the.nature of the photo-
conductivity relaxation of thin samples if the oscillogram shows two
exponents with widely differing time constants;.(2) by the constant T sh
of the short-term photocurrent component being inversely proportional
to the electric field aDDlieds whereas the constant of the long-term
component is independent of it; (3) by the fact that the long-term
component can be caused to vanish by the usual method of trap filling;
(4) by the long-term component increasing as the temperature decreases,
while the short-term component decreases and almost vanishes completely,
this being related to the intensified charge accumulation; in both cases
ln-r = f(l/T) follows a linear course4 (5) by the results obtained in a
study of the kinetics of the field effect also indicating a disturbance
of bipolarity. This bipolarity is also indicated by the field dependence
0 .0 r
sh and -r1and (7) it is particularly pronounced in samples kept on
air for a longer period of time after they had b 'een etched. (8) Experiments
on the condenser photo-emf proved that the disturbance of the photocurrent
bipolarity of Si is related to a change'in the surface charge. Such,a
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S/181/62/004/010/045/063
Minority carrier adhesion on B102/B112
disturbance occurs when Cn exp Etv- p ne