Measuring Diffusion Lengths in Epitaxial Silicon by Surface Photovoltage

ABSTRACTIn CMOS, the use of epitaxial layers for prevention of latch-up in logic technologies is well-known and pervasive. One of the crucial parameters is the amount of metallic contamination due to transition metals such as Fe in the epi since this phenomena effects both device performance and quality. However, the ability to measure this parameter on product material is not generally available due to inherent problems with most known methods. The limitation of traditional surface photovoltage is that the deep optical penetration of over a hundred microns is well-beyond the depth of most epitaxial layers and does not accurately profile the epitaxial region [1]. In this paper we report on the application of optical surface photovoltage (SPV) using a set of ultra-shallow optical filters to both quantify and qualify as-grown epitaxial layers on CZ P-type silicon. We believe that a non-contact, SPV measurement of Fe concentration and diffusion lengths within an epitaxial region has not been previously reported.

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Identification of Cr in p‐type silicon using the minority carrier lifetime measurement by the surface photovoltage method

Applied Physics Letters ◽

10.1063/1.116574 ◽

1996 ◽

Vol 68 (23) ◽

pp. 3281-3283 ◽

Cited By ~ 33

Author(s):

Kamal Mishra

Keyword(s):

Carrier Lifetime ◽

Minority Carrier ◽

Minority Carrier Lifetime ◽

Lifetime Measurement ◽

Surface Photovoltage ◽

Type Silicon ◽

P Type

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NOISE AND DIFFUSION IN p-TYPE SILICON

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1988433 ◽

1988 ◽

Vol 49 (C4) ◽

pp. C4-165-C4-168

Author(s):

J. P. NOUGIER ◽

A. MOATADID ◽

J. C. VAISSIERE

Keyword(s):

Type Silicon ◽

P Type ◽

And Diffusion

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Rapid Diffusion of Molybdenum Trace Contamination in Silicon

MRS Proceedings ◽

10.1557/proc-36-43 ◽

1984 ◽

Vol 36 ◽

Cited By ~ 5

Author(s):

S. P. Tobin ◽

A. C. Greenwald ◽

R. G. Wolfson ◽

D. L. Meier ◽

P. J. Drevinsky

Keyword(s):

Diffusion Coefficient ◽

Transition Metals ◽

Lower Limit ◽

Minority Carrier ◽

Diffusion Length ◽

Deep Level ◽

Depth Profiling ◽

Epitaxial Layers ◽

Epitaxial Silicon ◽

Rapid Diffusion

ABSTRACTMolybdenum contamination has been detected in silicon epitaxial layers and substrate wafers after processing in any one of several epitaxial silicon reactors. Greatly reduced minority carrier diffusion lengths and lifetimes are consistent with Mo concentrations measured by DLTS in the 1012 and 1013 cm−3 ranges. Depth profiling of diffusion length and the Mo deep level show much greater penetration than expected from previous reports of Mo as a slow diffuser. The data indicate a lower limit of 10−8 cm2/sec for the diffusion coefficient of Mo in silicon at 1200°C, consistent with high diffusivities measured for other transition metals.

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An Optical Approach to Evaluating the Effects of Chlorine on the Quality Of Si/SiO2 Interfaces

MRS Proceedings ◽

10.1557/proc-428-429 ◽

1996 ◽

Vol 428 ◽

Cited By ~ 1

Author(s):

Julia Sherry ◽

John Lowell ◽

Tim Hossain ◽

Damon Debusk

Keyword(s):

Alkali Metals ◽

Contact Potential Difference ◽

Environmental Concerns ◽

Device Performance ◽

Optical Surface ◽

Contact Potential ◽

High Injection ◽

Injection Frequency ◽

P Type

AbstractIn CMOS, the addition of chlorine particularly in TCA form to the growth of thermal oxides in logic technologies is well-known and pervasive. In addition to the increasing environmental concerns of chlorine use, one of the important parameters is the amount of metallic contamination due to transition metals such as Fe in the Si, and alkali metals like Na in the oxide since these phenomena effect both device performance and quality. However, the ability to measure this parameter on product material is not generally available due to inherent problems with most known methods. In this paper we report on the application of high-injection, frequency based optical surface photovoltage (SPV) and a more recent technique known as a contact potential difference (CPD) to both quantify and qualify as-grown oxides on CZ P-type silicon.

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Ultrasound Defect Engineering of Transition Metals Via Metal-Acceptor Pairs in Silicon

MRS Proceedings ◽

10.1557/proc-378-647 ◽

1995 ◽

Vol 378 ◽

Cited By ~ 2

Author(s):

Ronald E. Bell ◽

Serguei Ostapenko ◽

Jacek Lagowski

Keyword(s):

Minority Carrier ◽

Diffusion Length ◽

Surface Photovoltage ◽

Defect Engineering ◽

Acceptor Reaction ◽

Minority Carrier Diffusion Length ◽

Enhanced Diffusion ◽

Type Silicon ◽

P Type

AbstractExperimental evidence is provided for ultrasound stimulated dissociation of metal-acceptor pairs in silicon, and also for enhanced diffusion of metal interstitials which may lead to enhanced pairing. The first effect is found dominant in Fe-doped p-type silicon where ultrasound causes low temperature dissociation of Fe-B pairs. This is in contrast to Cr-doped p-type silicon where ultrasound enhances the formation of Cr-B pairs due to enhanced diffusivity of Cr by as much as two orders of magnitude.In this study, the metal-acceptor reaction was monitored in situ via corresponding changes of the minority carrier diffusion length measured by non-contact surface photovoltage. Ultrasound-stimulated pair reaction can be utilized for metal diagnostics for the silicon IC industry. Thus, with ultrasound, Cr-B pairing can be reduced from months to hours, making possible the identification of Cr via pairing kinetics in a reasonable period of time.

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