Matthew Wormington - Profile on Academia.edu (original) (raw)
Papers by Matthew Wormington
Model-free measurement of lateral recess in gate-all-around transistors with micro hard-X-ray fluorescence
Journal of Micro/Nanopatterning, Materials, and Metrology
In-line characterization of hetero bipolar transistor base layers and pMOS devices with embedded SiGe by high-resolution x-ray diffraction
Peer reviewe
Advances in X-Ray Analysis, 1993
A review of the methods of characterization of materials using X-rays incident at grazing angles ... more A review of the methods of characterization of materials using X-rays incident at grazing angles is presented. The rationale of all such methods is the need to obtain information from near-surface regions. The methods include grazing incidence diffraction, reflectivity, diffuse scatter and fluorescence. The experimental techniques are outlined, and the information obtainable and the methods of interpretation are discussed,
Benefit of combining metrology techniques for thin SiGe:B layers
25th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC 2014), 2014
ABSTRACT
Specular and off‐specular x‐ray reflectivity study of ion irradiated Co/Pt multilayers
Surface and Interface Analysis, 2004
Co/Pt thin film superlattices with strong perpendicular anisotropy and out‐of‐plane coercivities ... more Co/Pt thin film superlattices with strong perpendicular anisotropy and out‐of‐plane coercivities of 5–11 kOe were irradiated with Xe+ ions to tailor their magnetic properties. Specular and off‐specular x‐ray reflectivity (XRR) studies were performed to correlate the irradiation‐induced coercivity reduction with changes of the interfacial properties. Off‐specular XRR turned out to be particularly sensitive to the Co/Pt superlattice period. By applying the distorted wave Born approximation to simulate the diffusely scattered intensity, we were able to quantify the vertical roughness correlation throughout the superlattice stack. Study of a Co/Pt multilayer exposed to different Xe+ ion doses suggests that progressive ion bombardment causes a gradual loss of conformality between the different interfaces and a change of the interface morphology, whereas initial vertical RMS roughness values are not affected. Copyright © 2004 John Wiley & Sons, Ltd.
X-ray diffraction and reflectivity characterization of SiGe superlattice structures
Semiconductor Science and Technology, 1992
The authors demonstrate the effectiveness of both X-ray diffraction and X-ray reflectivity in the... more The authors demonstrate the effectiveness of both X-ray diffraction and X-ray reflectivity in the structural characterization of semiconductor structures. By combining information from both techniques the abruptness of the interfaces for Si1-xGex structures, with x=0.1-0.57, may be determined. For superlattice structures with x<0.3 both types of interface were found to have a root mean square (RMS) roughness of 0.5+or-0.3 nm.
Measurement of Surface Roughnesses and Topography at Nanometer Levels by Diffuse X-Ray Scattering
CIRP Annals - Manufacturing Technology, 1994
Instrumentation for diffuse X-ray scattering has recently been improved to the point at which mea... more Instrumentation for diffuse X-ray scattering has recently been improved to the point at which measurements may be made in a laboratory instrument in times that are competitive with stylus instruments for areal scans on high-quality surfaces. Theoretical models have also been implemented with efficient algorithms that permit rapid extraction of surface roughness, spatial bandwidth and correlation length from the data. The method is non-contacting, does not depend on detailed knowledge of optical constants, and gives information on roughnesses between 0.05 and 5 nm, on correlation lengths from sub-nanometre to tens of micrometres and on fractal dimensions between 2 and 2.95. The X-ray method is compared to atomic-force microscopy, and is shown to give similar results for a specimen measurable by each technique, but also to have greater speed and vastly reduced data acquisition requirements when averaged data are sought. The X-ray methods have a lower cut-off length and are both non-contacting and non-destructive. An application to high-quality Zerodur surfaces is shown.
Inline monitoring of SiGe strain relaxed buffers (SRBs) using high-resolution X-ray diffraction: AM: Advanced metrology
2016 27th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC), 2016
We describe the use of high resolution X-ray diffraction (HRXRD) for inline metrology of strain r... more We describe the use of high resolution X-ray diffraction (HRXRD) for inline metrology of strain relaxed buffer (SRB) layers and epitaxial layers grown thereon. The use of SRBs as a virtual substrate is a promising candidate for advanced CMOS logic at the 7 nm technology node and presents some unique challenges to traditional HRXRD measurements. To overcome these challenges, reciprocal space maps (RSMs) were employed to characterize different films on SRBs. We discuss the measurement strategies and recent improvements to X-ray metrology tools that enable these measurements for inline process control. Furthermore, advances in the automated data extraction and analysis are introduced.
Acta Crystallographica Section A Foundations of Crystallography, 1996
Physica B: Condensed Matter, 1998
Grazing incidence diffuse X-ray scattering data from a Co-Cu multilayer with stepped interfaces g... more Grazing incidence diffuse X-ray scattering data from a Co-Cu multilayer with stepped interfaces grown by molecular beam epitaxy on a copper silicide buffer on a silicon substrate has been analysed using a computer code based on a fractal interface within the distorted wave Born approximation. We have extended the theory to include the scattering from a stepped interface and have shown that a single set of structural parameters can be used to obtain an excellent agreement between simulation and experimental data taken under very different X-ray optical conditions. The symmetry of the diffuse scatter on rotation about the surface normal can be explained if it arises from step bunching at the ends of extensive flat terraces. These steps have a self-affine nature, enabling the fractal model to be used successfully. 1998 Elsevier Science B.V. All rights reserved.
Grazing incidence X-ray scattering measurement of silicate glass surfaces
Journal of Non-Crystalline Solids, 1999
ABSTRACT
Deep learning for the analysis of x-ray scattering data from high-aspect ratio structures
Metrology, Inspection, and Process Control XXXVII
Inline metrology of high aspect ratio hole tilt and center line shift using small-angle x-ray scattering
Journal of micro/nanopatterning, materials, and metrology, Mar 22, 2023
MRS Proceedings, 1994
ABSTRACTGrazing incidence X-ray reflectivity may be used to measure surface topography including ... more ABSTRACTGrazing incidence X-ray reflectivity may be used to measure surface topography including roughness and correlation lengths to sub-nanometre precision. A study is made of a technically important surface, a carefully-polished specimen of Zerodur glass-ceramic, which has been measured by diffuse scatter of CuKα X-radiation and atomic-force profilometry methods. The data have been analysed in terms of a fractal representation of the surface correlation function. Results from the two methods agreed within their estimated errors, with the X-ray data showing roughnesses of 1.3 nm, correlation length of 1 μm and fractal parameter (bandwidth) of 0.35. The X-ray methods have a lower cut-off length, are much more rapid for averaged information and are both non-contacting and non-destructive. They also show potential for the study of interface roughness in thin films.
Thermal Degradation of SiGe Interfaces Studied by X-Ray Reflectivity and Diffraction
MRS Proceedings, 1991
ABSTRACTWe demonstrate the use of x-ray diffraction to provide accurate compositional information... more ABSTRACTWe demonstrate the use of x-ray diffraction to provide accurate compositional information, together with grazing incidence reflectivity to provide information on layer thicknesses and surface and interface roughnesses, on Si/Si1-xGex superlattice structures of less than 200nm total thickness.The quality of SiGe interfaces has been investigated in superlattices where x varies from 0.1 to 0.5. At low Ge compositions the interfaces are shown to be smooth to a few angstroms. However, as the Ge composition in the SiGe layer approaches 50%, severe roughness is observed at the SiGe to Si interfaces, although the Si to SiGe interfaces remain relatively smooth.Upon annealing for one hour at 850°C the Ge diffuses outwards from the SiGe layers and can be closely modelled by inclusion of a (2.4±0.3)nm linearly graded layer either side of the SiGe layer into a simulation program. The long range roughness at the SiGe to Si interface is lost upon annealing leaving only a short range roughn...
Strain and Compositional Analysis of (Si)Ge Fin Structures Using High Resolution X‐Ray Diffraction
physica status solidi c
HRXRD for in-line monitoring of advanced FD-SOI technology: Use-cases: AM: Advanced metrology
2016 27th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC), 2016
This paper describes specific applications illustrating the use of High Resolution X-Ray Diffract... more This paper describes specific applications illustrating the use of High Resolution X-Ray Diffraction (HRXRD) for the inline control of advanced logic technology nodes. More specifically, an innovative strategy based on HRXRD rocking-curve analysis is described for the control of epitaxial SiGe layers on Fully Depleted Silicon On Insulator (FD-SOI) wafers including consideration of the strategy for managing the tilt between the SOI layer and the bulk silicon substrate. Furthermore, the quality of HRXRD Reciprocal Space Maps (RSMs) obtained in an industrial environment is demonstrated and the benefit of RSMs for inline control is discussed.
ECS Meeting Abstracts, 2018
High-Resolution X-ray Diffraction (HRXRD) is a well-established technique for the characterizatio... more High-Resolution X-ray Diffraction (HRXRD) is a well-established technique for the characterization and metrology of epitaxial materials encountered in a variety of important technologies such as nano, opto and power electronics. Traditionally the technique was mainly used for blanket films, and this is still a significant application. However, complex epitaxial nanostructures continue to grow in importance to enable advanced CMOS logic transistors that must combine high-performance with low power consumption and cost with scaled dimensions. Hence, the need to measure and analyze such structures becomes necessary. Several new transistor architectures being considered for logic nodes beyond 10 nm, including more sophisticated FinFETs, gate-all-around (GAA) FETs and the use of fully-depleted silicon-on-insulator (FDSOI) substrates. Equally varied is the range of epitaxial materials proposed, which include SiGe, SiP, Ge as well as III-V materials. Each of these innovations has specific ...
X-ray critical dimension metrology solution for high aspect ratio semiconductor structures
Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV, 2021
We have developed a novel in-line solution for the characterization and metrology of high-aspect ... more We have developed a novel in-line solution for the characterization and metrology of high-aspect ratio (HAR) semiconductor structures using transmission small-angle X-ray scattering (SAXS). The solution consists of the Sirius-XCD® tool, NanoDiffract for XCD (NDX) analysis software and high-performance computing infrastructure. The solution provides quantitative information on the orientation and shape of HAR structures, such as 3D NAND channel holes and DRAM capacitors, and can be used for development and control of the critical etch processes used in the formation of such structures. The tool has been designed to minimize expensive cleanroom space without sacrificing performance with typical measurements taking only a few minutes per site. The analysis is done using real-time regression in parallel to the measurements to maximize the throughput of the solution. We will illustrate the key features of the solution using data from a HAR reference wafer and provide results for hole shape and tilt across the wafer together with complimentary data from other techniques. We will also discuss future opportunities for both stand-alone XCD applications and possibilities of XCD-OCD synergies including hybrid metrology in solving complex high-aspect ratio (HAR) and other applications.
A giant magnetoresistance (GMR) multilayer spin-valve stack was investigated utilizing X-ray diff... more A giant magnetoresistance (GMR) multilayer spin-valve stack was investigated utilizing X-ray diffraction (XRD), reflectivity (XRR) and cross-section transmission electron microscopy (XTEM). X-ray reflectivity analysis indicated that layer thickness and density values were within 10% percent of the nominal values with the exception of CoFe and Cu layers, both of which possessed lower than nominal thickness and density. Interface roughness/interdiffusion increased progressively from the substrate (2 A) to the surface (20 A) of the samples, especially with the addition of the antiferromagnetic NiMn layer. The top Ta layer possessed a thin (20 A), low-density oxide and the buried Ta/NiFe interface was deemed to be associated with a thin (18 A) low density Ta layer at the interface. X-ray diffraction analysis showed that the NiFe/CoFe/Cu/CoFe layers possess a single, sharp ( 11 l}fcc/(OO2)hcp fiber texture. A complex structural evolution was found to be associated with deposition of the ...
Model-free measurement of lateral recess in gate-all-around transistors with micro hard-X-ray fluorescence
Journal of Micro/Nanopatterning, Materials, and Metrology
In-line characterization of hetero bipolar transistor base layers and pMOS devices with embedded SiGe by high-resolution x-ray diffraction
Peer reviewe
Advances in X-Ray Analysis, 1993
A review of the methods of characterization of materials using X-rays incident at grazing angles ... more A review of the methods of characterization of materials using X-rays incident at grazing angles is presented. The rationale of all such methods is the need to obtain information from near-surface regions. The methods include grazing incidence diffraction, reflectivity, diffuse scatter and fluorescence. The experimental techniques are outlined, and the information obtainable and the methods of interpretation are discussed,
Benefit of combining metrology techniques for thin SiGe:B layers
25th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC 2014), 2014
ABSTRACT
Specular and off‐specular x‐ray reflectivity study of ion irradiated Co/Pt multilayers
Surface and Interface Analysis, 2004
Co/Pt thin film superlattices with strong perpendicular anisotropy and out‐of‐plane coercivities ... more Co/Pt thin film superlattices with strong perpendicular anisotropy and out‐of‐plane coercivities of 5–11 kOe were irradiated with Xe+ ions to tailor their magnetic properties. Specular and off‐specular x‐ray reflectivity (XRR) studies were performed to correlate the irradiation‐induced coercivity reduction with changes of the interfacial properties. Off‐specular XRR turned out to be particularly sensitive to the Co/Pt superlattice period. By applying the distorted wave Born approximation to simulate the diffusely scattered intensity, we were able to quantify the vertical roughness correlation throughout the superlattice stack. Study of a Co/Pt multilayer exposed to different Xe+ ion doses suggests that progressive ion bombardment causes a gradual loss of conformality between the different interfaces and a change of the interface morphology, whereas initial vertical RMS roughness values are not affected. Copyright © 2004 John Wiley & Sons, Ltd.
X-ray diffraction and reflectivity characterization of SiGe superlattice structures
Semiconductor Science and Technology, 1992
The authors demonstrate the effectiveness of both X-ray diffraction and X-ray reflectivity in the... more The authors demonstrate the effectiveness of both X-ray diffraction and X-ray reflectivity in the structural characterization of semiconductor structures. By combining information from both techniques the abruptness of the interfaces for Si1-xGex structures, with x=0.1-0.57, may be determined. For superlattice structures with x<0.3 both types of interface were found to have a root mean square (RMS) roughness of 0.5+or-0.3 nm.
Measurement of Surface Roughnesses and Topography at Nanometer Levels by Diffuse X-Ray Scattering
CIRP Annals - Manufacturing Technology, 1994
Instrumentation for diffuse X-ray scattering has recently been improved to the point at which mea... more Instrumentation for diffuse X-ray scattering has recently been improved to the point at which measurements may be made in a laboratory instrument in times that are competitive with stylus instruments for areal scans on high-quality surfaces. Theoretical models have also been implemented with efficient algorithms that permit rapid extraction of surface roughness, spatial bandwidth and correlation length from the data. The method is non-contacting, does not depend on detailed knowledge of optical constants, and gives information on roughnesses between 0.05 and 5 nm, on correlation lengths from sub-nanometre to tens of micrometres and on fractal dimensions between 2 and 2.95. The X-ray method is compared to atomic-force microscopy, and is shown to give similar results for a specimen measurable by each technique, but also to have greater speed and vastly reduced data acquisition requirements when averaged data are sought. The X-ray methods have a lower cut-off length and are both non-contacting and non-destructive. An application to high-quality Zerodur surfaces is shown.
Inline monitoring of SiGe strain relaxed buffers (SRBs) using high-resolution X-ray diffraction: AM: Advanced metrology
2016 27th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC), 2016
We describe the use of high resolution X-ray diffraction (HRXRD) for inline metrology of strain r... more We describe the use of high resolution X-ray diffraction (HRXRD) for inline metrology of strain relaxed buffer (SRB) layers and epitaxial layers grown thereon. The use of SRBs as a virtual substrate is a promising candidate for advanced CMOS logic at the 7 nm technology node and presents some unique challenges to traditional HRXRD measurements. To overcome these challenges, reciprocal space maps (RSMs) were employed to characterize different films on SRBs. We discuss the measurement strategies and recent improvements to X-ray metrology tools that enable these measurements for inline process control. Furthermore, advances in the automated data extraction and analysis are introduced.
Acta Crystallographica Section A Foundations of Crystallography, 1996
Physica B: Condensed Matter, 1998
Grazing incidence diffuse X-ray scattering data from a Co-Cu multilayer with stepped interfaces g... more Grazing incidence diffuse X-ray scattering data from a Co-Cu multilayer with stepped interfaces grown by molecular beam epitaxy on a copper silicide buffer on a silicon substrate has been analysed using a computer code based on a fractal interface within the distorted wave Born approximation. We have extended the theory to include the scattering from a stepped interface and have shown that a single set of structural parameters can be used to obtain an excellent agreement between simulation and experimental data taken under very different X-ray optical conditions. The symmetry of the diffuse scatter on rotation about the surface normal can be explained if it arises from step bunching at the ends of extensive flat terraces. These steps have a self-affine nature, enabling the fractal model to be used successfully. 1998 Elsevier Science B.V. All rights reserved.
Grazing incidence X-ray scattering measurement of silicate glass surfaces
Journal of Non-Crystalline Solids, 1999
ABSTRACT
Deep learning for the analysis of x-ray scattering data from high-aspect ratio structures
Metrology, Inspection, and Process Control XXXVII
Inline metrology of high aspect ratio hole tilt and center line shift using small-angle x-ray scattering
Journal of micro/nanopatterning, materials, and metrology, Mar 22, 2023
MRS Proceedings, 1994
ABSTRACTGrazing incidence X-ray reflectivity may be used to measure surface topography including ... more ABSTRACTGrazing incidence X-ray reflectivity may be used to measure surface topography including roughness and correlation lengths to sub-nanometre precision. A study is made of a technically important surface, a carefully-polished specimen of Zerodur glass-ceramic, which has been measured by diffuse scatter of CuKα X-radiation and atomic-force profilometry methods. The data have been analysed in terms of a fractal representation of the surface correlation function. Results from the two methods agreed within their estimated errors, with the X-ray data showing roughnesses of 1.3 nm, correlation length of 1 μm and fractal parameter (bandwidth) of 0.35. The X-ray methods have a lower cut-off length, are much more rapid for averaged information and are both non-contacting and non-destructive. They also show potential for the study of interface roughness in thin films.
Thermal Degradation of SiGe Interfaces Studied by X-Ray Reflectivity and Diffraction
MRS Proceedings, 1991
ABSTRACTWe demonstrate the use of x-ray diffraction to provide accurate compositional information... more ABSTRACTWe demonstrate the use of x-ray diffraction to provide accurate compositional information, together with grazing incidence reflectivity to provide information on layer thicknesses and surface and interface roughnesses, on Si/Si1-xGex superlattice structures of less than 200nm total thickness.The quality of SiGe interfaces has been investigated in superlattices where x varies from 0.1 to 0.5. At low Ge compositions the interfaces are shown to be smooth to a few angstroms. However, as the Ge composition in the SiGe layer approaches 50%, severe roughness is observed at the SiGe to Si interfaces, although the Si to SiGe interfaces remain relatively smooth.Upon annealing for one hour at 850°C the Ge diffuses outwards from the SiGe layers and can be closely modelled by inclusion of a (2.4±0.3)nm linearly graded layer either side of the SiGe layer into a simulation program. The long range roughness at the SiGe to Si interface is lost upon annealing leaving only a short range roughn...
Strain and Compositional Analysis of (Si)Ge Fin Structures Using High Resolution X‐Ray Diffraction
physica status solidi c
HRXRD for in-line monitoring of advanced FD-SOI technology: Use-cases: AM: Advanced metrology
2016 27th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC), 2016
This paper describes specific applications illustrating the use of High Resolution X-Ray Diffract... more This paper describes specific applications illustrating the use of High Resolution X-Ray Diffraction (HRXRD) for the inline control of advanced logic technology nodes. More specifically, an innovative strategy based on HRXRD rocking-curve analysis is described for the control of epitaxial SiGe layers on Fully Depleted Silicon On Insulator (FD-SOI) wafers including consideration of the strategy for managing the tilt between the SOI layer and the bulk silicon substrate. Furthermore, the quality of HRXRD Reciprocal Space Maps (RSMs) obtained in an industrial environment is demonstrated and the benefit of RSMs for inline control is discussed.
ECS Meeting Abstracts, 2018
High-Resolution X-ray Diffraction (HRXRD) is a well-established technique for the characterizatio... more High-Resolution X-ray Diffraction (HRXRD) is a well-established technique for the characterization and metrology of epitaxial materials encountered in a variety of important technologies such as nano, opto and power electronics. Traditionally the technique was mainly used for blanket films, and this is still a significant application. However, complex epitaxial nanostructures continue to grow in importance to enable advanced CMOS logic transistors that must combine high-performance with low power consumption and cost with scaled dimensions. Hence, the need to measure and analyze such structures becomes necessary. Several new transistor architectures being considered for logic nodes beyond 10 nm, including more sophisticated FinFETs, gate-all-around (GAA) FETs and the use of fully-depleted silicon-on-insulator (FDSOI) substrates. Equally varied is the range of epitaxial materials proposed, which include SiGe, SiP, Ge as well as III-V materials. Each of these innovations has specific ...
X-ray critical dimension metrology solution for high aspect ratio semiconductor structures
Metrology, Inspection, and Process Control for Semiconductor Manufacturing XXXV, 2021
We have developed a novel in-line solution for the characterization and metrology of high-aspect ... more We have developed a novel in-line solution for the characterization and metrology of high-aspect ratio (HAR) semiconductor structures using transmission small-angle X-ray scattering (SAXS). The solution consists of the Sirius-XCD® tool, NanoDiffract for XCD (NDX) analysis software and high-performance computing infrastructure. The solution provides quantitative information on the orientation and shape of HAR structures, such as 3D NAND channel holes and DRAM capacitors, and can be used for development and control of the critical etch processes used in the formation of such structures. The tool has been designed to minimize expensive cleanroom space without sacrificing performance with typical measurements taking only a few minutes per site. The analysis is done using real-time regression in parallel to the measurements to maximize the throughput of the solution. We will illustrate the key features of the solution using data from a HAR reference wafer and provide results for hole shape and tilt across the wafer together with complimentary data from other techniques. We will also discuss future opportunities for both stand-alone XCD applications and possibilities of XCD-OCD synergies including hybrid metrology in solving complex high-aspect ratio (HAR) and other applications.
A giant magnetoresistance (GMR) multilayer spin-valve stack was investigated utilizing X-ray diff... more A giant magnetoresistance (GMR) multilayer spin-valve stack was investigated utilizing X-ray diffraction (XRD), reflectivity (XRR) and cross-section transmission electron microscopy (XTEM). X-ray reflectivity analysis indicated that layer thickness and density values were within 10% percent of the nominal values with the exception of CoFe and Cu layers, both of which possessed lower than nominal thickness and density. Interface roughness/interdiffusion increased progressively from the substrate (2 A) to the surface (20 A) of the samples, especially with the addition of the antiferromagnetic NiMn layer. The top Ta layer possessed a thin (20 A), low-density oxide and the buried Ta/NiFe interface was deemed to be associated with a thin (18 A) low density Ta layer at the interface. X-ray diffraction analysis showed that the NiFe/CoFe/Cu/CoFe layers possess a single, sharp ( 11 l}fcc/(OO2)hcp fiber texture. A complex structural evolution was found to be associated with deposition of the ...