(Invited) Scanning Probe Microscopes for Subsurface Imaging

Kopanski, Joseph J.; You, Lin; Ahn, Jungjoon; Hitz, Emily; Obeng, Yaw S.

doi:10.1149/06102.0185ecst

“…19,28 We are interested in metrology for the accurate quantification and mechanistic understanding of the reliability issues associated with the back-end-of-the-line (BEOL) metallization in emerging nanoelectronic devices. [18][19][20][21][22][23][24][25] The objective of this work is to shed some light on the thermal stability of prototypical emerging low-k dielectric films, as a function of material type and deposition methods, and to relate the thermally-induced changes in chemical properties that occur within the films. In this work, timed thermal storage at modest processing temperatures (200°C, under nitrogen) was used as the perturbation stress to examine the impact of heat on the electrical behavior of un-patterned thin films of the low-k material samples on silicon substrates.…”

Section: Nist Author Manuscriptmentioning

confidence: 99%

Broadband Dielectric Spectroscopic Characterization of Thermal Stability of Low-k Dielectric Thin Films for Micro- and Nanoelectronic Applications

Sunday

¹

,

Montgomery²,

Amoah³

et al. 2017

Self Cite

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In this paper, we discuss the use of broadband microwaves (MW) to characterize the thermal stability of organic and hybrid silicon-organic thin films meant for insulation applications in micro-and nanoelectronic devices. We take advantage of MW propagation characteristics to extract and examine the relationships between electrical properties and the chemistry of prototypical low-k materials. The impact of thermal anneal at modest temperatures is examined to shed light on the thermal-induced performance and reliability changes within the dielectric films. These changes are then correlated with the chemical changes in the films, and could provide basis for rational selection of organic dielectrics for integrated devices.Semiconductor manufacturers have been shrinking transistor size in integrated circuits (IC) to improve chip performance and energy efficiency. Consequently, interconnect delay has become a bottle neck for advanced very-large-scale integration (VLSI) systems, and new materials are needed for technology nodes beyond 22 nm to address this problem. 1 The introduction of emerging materials comes with a myriad of reliability issues arising primarily from the thermomechanical properties of the new materials. In contrast with conventional silicon oxides, low-and ultra-low dielectric constant (i.e., low-k and ULK) materials, with tunable dielectric constants, tend to have decreased thermal performance and diminished mechanical properties. [2][3][4] Due to the differences in the thermal, chemical and mechanical properties of these materials, stress can build up within the integrated systems that use these new materials, and may cause mechanical damage. The low-k dielectric materials have different coefficients of thermal expansion from the metals they clad, which leads to the formation of strong local tensile stresses and thermal issues, particularly if the device is thermally cycled in the broad processing temperature range of 25°C to 450°C. With many of the emerging dielectric materials, repeated thermal cycling results in molecular and structural changes, such that the lowest-lying dielectric layer may not have the same properties as the back-end-of line dielectrics of the same composition which have beenThis is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. * Electrochemical Society Member. z yaw.obeng@nist.gov Author ManuscriptAccepted for publication in a peer-reviewed journal National Institute of Standards and Technology • U.S. Department of CommercePublished in final edited form as: ECS J Solid State Sci Technol. 2017 ; 6(9): N155-N162. doi:10.1149/2.0141709jss. NIST Author ManuscriptNIST Author Manuscript NIST Author Manuscript exposed to fewer thermal cycles. These material changes can have significant impact on the performance and reliability of the integrated system because the ...

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“…5,6 Atomic force microscopy (AFM) has been widely used as a nanoscale measurement tool. [7][8][9][10][11][12][13] AFM-based nano-indentation has also been used as a fast and straightforward method to study the surface deformation, [14][15][16][17][18] the nanoscale hardness, the stiffness, and the elastic modulus of materials, with the aid of contact mechanics models of materials. [19][20][21][22] Besides the metrological applications, AFM technology has also been used to manipulate the local physico-chemical properties of materials.…”

Section: Introductionmentioning

confidence: 99%

Probe assisted localized doping of aluminum into silicon substrates

Ahn

¹

,

Solares

²

,

You

³

et al. 2019

Journal of Applied Physics

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0

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Precise control of dopant placement is crucial for the reproducible, and reliable, nanoscale semiconductor device fabrication. In this paper, we demonstrate an atomic force microscopy (AFM) probe assisted localized doping of aluminum into an n-type silicon (100) wafer to generate nanoscale counter-doped junctions within two nanometers of the silicon-air interface. The local doping results in changes in electrostatic potential, which are reported as contact potential difference, with nanoscale spatial resolution. In contrast to the literature where nano-mechanical defects in, or contaminants on, silicon substrates can result in measurable changes in the chemical potential of the near-surface, additional thermal treatment was needed to electrically activate the aluminum dopants in our current work. Unfortunately, the thermal activation step also caused the dopants to diffuse and geometric distortions in the doped area, i.e., broadening and blurring of the electrically distinct areas. The results from optimization efforts show that the "active" dopant concentration depended primarily on the thermal anneal temperature; additional AFM-tip dwell time during the aluminum implantation step had no meaningful impact on the electrical activity of the doped sites.

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“…19,28 We are interested in metrology for the accurate quantification and mechanistic understanding of the reliability issues associated with the back-end-of-the-line (BEOL) metallization in emerging nanoelectronic devices. [18][19][20][21][22][23][24][25] The objective of this work is to shed some light on the thermal stability of prototypical emerging low-k dielectric films, as a function of material type and deposition methods, and to relate the thermally-induced changes in chemical properties that occur within the films. In this work, timed thermal storage at modest processing temperatures (200°C, under nitrogen) was used as the perturbation stress to examine the impact of heat on the electrical behavior of un-patterned thin films of the low-k material samples on silicon substrates.…”

mentioning

confidence: 99%

Broadband Dielectric Spectroscopic Characterization of Thermal Stability of Low-k Dielectric Thin Films for Micro- and Nanoelectronic Applications

Sunday,

Montgomery,

Amoah

et al. 2017

Meet. Abstr.

Self Cite

0

View full text Add to dashboard Cite

In this paper, we discuss the use of broadband microwaves (MW) to characterize the thermal stability of organic and hybrid silicon-organic thin films meant for insulation applications in micro-and nanoelectronic devices. We take advantage of MW propagation characteristics to extract and examine the relationships between electrical properties and the chemistry of prototypical low-k materials. The impact of thermal anneal at modest temperatures is examined to shed light on the thermal-induced performance and reliability changes within the dielectric films. These changes are then correlated with the chemical changes in the films, and could provide basis for rational selection of organic dielectrics for integrated devices.Semiconductor manufacturers have been shrinking transistor size in integrated circuits (IC) to improve chip performance and energy efficiency. Consequently, interconnect delay has become a bottle neck for advanced very-large-scale integration (VLSI) systems, and new materials are needed for technology nodes beyond 22 nm to address this problem. 1 The introduction of emerging materials comes with a myriad of reliability issues arising primarily from the thermomechanical properties of the new materials. In contrast with conventional silicon oxides, low-and ultra-low dielectric constant (i.e., low-k and ULK) materials, with tunable dielectric constants, tend to have decreased thermal performance and diminished mechanical properties. [2][3][4] Due to the differences in the thermal, chemical and mechanical properties of these materials, stress can build up within the integrated systems that use these new materials, and may cause mechanical damage. The low-k dielectric materials have different coefficients of thermal expansion from the metals they clad, which leads to the formation of strong local tensile stresses and thermal issues, particularly if the device is thermally cycled in the broad processing temperature range of 25°C to 450°C. With many of the emerging dielectric materials, repeated thermal cycling results in molecular and structural changes, such that the lowest-lying dielectric layer may not have the same properties as the back-end-of line dielectrics of the same composition which have beenThis is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. * Electrochemical Society Member. z yaw.obeng@nist.gov

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(Invited) Scanning Probe Microscopes for Subsurface Imaging

Cited by 17 publications

References 3 publications

Broadband Dielectric Spectroscopic Characterization of Thermal Stability of Low-k Dielectric Thin Films for Micro- and Nanoelectronic Applications

Broadband Dielectric Spectroscopic Characterization of Thermal Stability of Low-k Dielectric Thin Films for Micro- and Nanoelectronic Applications

Probe assisted localized doping of aluminum into silicon substrates

Broadband Dielectric Spectroscopic Characterization of Thermal Stability of Low-k Dielectric Thin Films for Micro- and Nanoelectronic Applications

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