Mikhail Baklanov - Academia.edu (original) (raw)

Papers by Mikhail Baklanov

Solid State Communications

ABSTRACT

CF 3 I was suggested as a replacement of CF 4 gas to decrease the plasma-induced damage (PID) on ... more CF 3 I was suggested as a replacement of CF 4 gas to decrease the plasma-induced damage (PID) on low-k dielectrics during etching. This proposal is investigated by means of plasma emission measurements and material characterisation. The experiments were conducted in a 300 mm capacitively coupled plasma source. The vacuum ultraviolet (VUV, λ 30 220 ⩽ ⩽ nm) plasma emission was measured for discharges generated in a pure or a mixture of argon, CF 4 and/or CF 3 I, since VUV plays a major role in PID. However, CF 3 I containing discharges were found to have a stronger emission than CF 4 in the VUV range. Nevertheless, Fourier transform infrared spectroscopy and κ-value measurements showed that there is almost no difference between the damage caused by CF 3 I or CF 4 containing plasmas, while etching in a capacitively coupled plasma source. It is proposed that the damage caused by CF 3 I with lower F * -density but higher VUV-photon flux is similar to the damage caused by CF 4 , with higher F * -density but lower VUV-photon flux.

Reactivity of Solids

ABSTRACT

Proceedings of the IEEE 2001 International Interconnect Technology Conference (Cat. No.01EX461), 2001

ABSTRACT Silicon-Oxy-Carbide (SiOC) materials are used as low-k materials for the 2.7-k generatio... more ABSTRACT Silicon-Oxy-Carbide (SiOC) materials are used as low-k materials for the 2.7-k generation. They can be etched with the fluorinated chemistries used for oxide but some optimizations are needed to achieve acceptable etch-rates and good selectivities. The resist strip is also very sensitive and requires even more development to keep the material properties intact after full damascene integration. Oxygen is useful but it can also cause severe damage. All experiments described in this paper were performed on Z3MSTM Low-k(*)

Porous glasses are widely used in microelectronics as inter-metal dielectrics with low dielectric... more Porous glasses are widely used in microelectronics as inter-metal dielectrics with low dielectric constant (so called low-k dielectrics). At the same time copper is used as a metal because of its low resistivity. Combination of Cu and low-k requires a barrier to prevent Cu diffusion into a low-k dielectric. Integrity of such a barrier becomes an issue when porous glass is used as a low-k dielectric. The barrier should be as thin as possible and fully dense at the same time. Using solvent (toluene) penetration through a barrier [tantalum nitride in our case, which is non-stoichiometric, hence denoted as Ta(N)] and adsorption in porous glass as a barrier integrity probe we show that barrier integrity depends not only on porous structure of the glass, but also on its chemical composition (namely on carbon content). Glasses with high carbon content are easier to seal with Ta(N) barrier. With help of Monte Carlo simulations, we speculate that different chemical composition of the porous glass results in different surface diffusion during barrier deposition. Different surface diffusion, in turn, results in different integrity of the porous barrier.

We review the latest studies that address the fundamental understanding of low-k dielectric elect... more We review the latest studies that address the fundamental understanding of low-k dielectric electrical properties and reliability. We focus on the results discussing the nature of process induced defects, leakage currents and breakdown behavior, as they are important factors to reveal material modification and damage. Issues related to the use of porogen based PECVD techniques during dielectric deposition are discussed, where we focus on the selection of matrix and porogen precursors and on the improvements related to post-deposition treatments. During damascene integration, low-k dielectrics are subjected to several processes that induce material damage, where we review recent learning about plasma exposure, barrier deposition and chemical mechanical polishing. In order to have a successful implementation of advanced ultralow-k films in back-end-of-line interconnects, we argue that more research efforts are needed with respect to its material development, integration and reliability and make some proposals for future work.

MRS Proceedings, 2001

KULeuven. ...

Porous organosilicate glasses (OSG) are important low-k candidates for advanced interconnects. Ho... more Porous organosilicate glasses (OSG) are important low-k candidates for advanced interconnects. However, their integration is very challenging because the etch/strip plasmas degrade their properties and reliability. This problem can be reduced by pore stuffing (for instance, by sacrificial polymers [1]) because it reduces penetration of active radicals and VUV light into the film. The pore stuffing by sacrificial organic polymers is interesting but has few challenges, such as its impact on several steps of the patterning and metallization and possible deformation of low-k film during the stuffing and un-stuffing. An alternative approach based on cryogenic low-k etch has recently been developed [2]. The initial plasma reactants and the reaction products can condense in the pores at cryogenic temperature and protect the low-k films against the plasma damage. Most of reaction products condensed in the pores become volatile at room temperature so the problem of their removal has a relati...

MRS Proceedings, 2001

ABSTRACT

Physical Review B, 2000

Low-temperature transport measurements on superconducting film-normal wire-superconducting film ͑... more Low-temperature transport measurements on superconducting film-normal wire-superconducting film ͑SNS͒ junctions fabricated on the basis of thin superconducting polycrystalline PtSi films are reported. Due to the perfectness of SN boundaries in the junctions, zero bias resistance dip related to pair current proximity effect and subharmonic energy gap structure originating from phase coherent multiple Andreev reflections have been observed and studied.

2011 IEEE International Interconnect Technology Conference, 2011

... P. Verdonck, A. Delabie, J. Swerts, L. Farrell, MR Baklanov, H. Tielens, E. Van Besien, J. Wi... more ... P. Verdonck, A. Delabie, J. Swerts, L. Farrell, MR Baklanov, H. Tielens, E. Van Besien, J. Witters, L. Nyns, S. Van Elshocht ... More accurate calculations of the depth and profile of deposited film have been done using Monte-Carlo simulations. ...

2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings, 2006

Degradation of porous low dielectric constant materials during their exposure in etch and strip p... more Degradation of porous low dielectric constant materials during their exposure in etch and strip plasmas is analyzed from point of view of surface chemistry and recombination of active radicals. Although the degree of damage during the etching can be significantly reduced, the damage in O 2 and H 2 based strip/cleaning plasma are more challenging. The plasma damage mechanisms are the main subject of this discussion. It is demonstrated why the degree of damage can be reduced using He and H 2 based plasmas at elevated processing temperature.

Semiconductor Science and Technology, 2014

A low-temperature multifrequency electron spin resonance (ESR) study has been carried out on Cz-(... more A low-temperature multifrequency electron spin resonance (ESR) study has been carried out on Cz-(110)Si/insulator structures with organosilicate films of low dielectric constant κ grown at 300°C using the plasma-enhanced chemical vapor deposition method (PECVD). After subjection to a short-term UV-irradiation-assisted thermal curing treatment at 430°C to remove the organic component from the low-κ film and obtain optimal porosity, the NL8 ESR spectrum of C 2v symmetry is observed, characterized by g 1 (//[100] = 1.999 83(8), g 2 (//[011] = 1.992 74(8), g 3 = (//[1 10]) = 2.001 15(8). Based on previous insight, this reveals the generation in the c-Si substrate of singly ionized thermal double donor (TDD) defects with a core containing oxygen atoms. Remarkably, the generation is found to be highly nonuniform, and the defect density depth profile shows an exponential-like decay (decay length ∼3.8 μm) from the oxide/Si interface inward the Si substrate, thus exposing the defect formation as an interface-administered effect. Upon analysis, the strain induced by interfacial stress in the c-Si beneath the interface is suggested as the major driving component in the enhancement of TDD formation during thermal treatment, suggesting that substantial stress is involved with PECVD organosilicate low-κ glasses. The result represents a different and affirmative illustration of the influence of strain on TDD formation. Based on the principal g values, the observed TDD is closest to the NL8 1 type, the one formed first in bulk c-Si through oxygen agglomeration during short-term thermal treatment.

2012 IEEE International Interconnect Technology Conference, 2012

ABSTRACT In this work we integrate an advanced k=2.3 spin-on polymer at 40nm ½ pitch. K-value res... more ABSTRACT In this work we integrate an advanced k=2.3 spin-on polymer at 40nm ½ pitch. K-value restoration techniques are investigated and complete k-value restoration is demonstrated using an in-situ HeH2 plasma. An EUV compatible stack and a dielectric dual hard mask scheme is developed to pattern trenches with good uniformity and low litho-etch bias. The impact of scaling the dielectric spacing and of direct CMP on time dependent dielectric breakdown is also studied.

In Atomic Layer Deposition (ALD), initial film growth depends on the chemical nature of the subst... more In Atomic Layer Deposition (ALD), initial film growth depends on the chemical nature of the substrate. Knowledge of the initial growth kinetics of ALD layers on different surface modified porous substrates is important, especially when ultrathin films of a few nanometers thick are needed [1]. The low-k community, for example, could use these insights for effective pore sealing of low-k materials [2]. By enhancing ALD growth in the near surface region as compared to the bulk part of a porous layer, the pores could be sealed off while maintaining porosity in the bulk. In this study three types of porous low-k (k=2.0, SiCOH [3]) films are used: a pristine containing Si-CH 3 surface groups, an O 2 plasma treated film containing Si-OH surface groups throughout the entire layer, and a H 2 /He plasma treated film where Si-OH groups were introduced only in the near-surface region. Deposition of TiO 2 was done in a low-vacuum home-built ALD reactor using tetrakis(dimethylamino) titanium (TDM...

MRS Proceedings, 2006

ABSTRACT Spin-on pure-silica-zeolite MFI films consist of zeolite nanocrystals embedded in a comp... more ABSTRACT Spin-on pure-silica-zeolite MFI films consist of zeolite nanocrystals embedded in a compacted silica matrix of zeolite primary nanoparticles. They appear to be promising as a low-k material due to their good mechanical properties and high microporosity, parallel to their intrinsic low k-value. Results are promising but the implementation of this material is still far away. To contribute to the implementation we present a study on the final film properties depending on the zeolite MFI nanocrystal size. Different techniques are used for the characterization: Dynamic Light Scattering, X-ray diffraction, Scanning Electron Microscopy, Nitrogen adsorption, EllipsoPorosimetry using toluene and NanoIndentation. The results show a clear dependence of the film properties on the nanocrystal size. Clearly, smaller nanocrystals provide better homogeneity, smaller pore size and higher mechanical properties. However, due to the hydrophilicity of the silica matrix lower k-values are only obtained for larger zeolite nanocrystals which provide with higher crystallinity in the films.

Materials Science in Semiconductor Processing, 1998

ABSTRACT

Solid State Communications

ABSTRACT

CF 3 I was suggested as a replacement of CF 4 gas to decrease the plasma-induced damage (PID) on ... more CF 3 I was suggested as a replacement of CF 4 gas to decrease the plasma-induced damage (PID) on low-k dielectrics during etching. This proposal is investigated by means of plasma emission measurements and material characterisation. The experiments were conducted in a 300 mm capacitively coupled plasma source. The vacuum ultraviolet (VUV, λ 30 220 ⩽ ⩽ nm) plasma emission was measured for discharges generated in a pure or a mixture of argon, CF 4 and/or CF 3 I, since VUV plays a major role in PID. However, CF 3 I containing discharges were found to have a stronger emission than CF 4 in the VUV range. Nevertheless, Fourier transform infrared spectroscopy and κ-value measurements showed that there is almost no difference between the damage caused by CF 3 I or CF 4 containing plasmas, while etching in a capacitively coupled plasma source. It is proposed that the damage caused by CF 3 I with lower F * -density but higher VUV-photon flux is similar to the damage caused by CF 4 , with higher F * -density but lower VUV-photon flux.

Reactivity of Solids

ABSTRACT

Proceedings of the IEEE 2001 International Interconnect Technology Conference (Cat. No.01EX461), 2001

ABSTRACT Silicon-Oxy-Carbide (SiOC) materials are used as low-k materials for the 2.7-k generatio... more ABSTRACT Silicon-Oxy-Carbide (SiOC) materials are used as low-k materials for the 2.7-k generation. They can be etched with the fluorinated chemistries used for oxide but some optimizations are needed to achieve acceptable etch-rates and good selectivities. The resist strip is also very sensitive and requires even more development to keep the material properties intact after full damascene integration. Oxygen is useful but it can also cause severe damage. All experiments described in this paper were performed on Z3MSTM Low-k(*)

Porous glasses are widely used in microelectronics as inter-metal dielectrics with low dielectric... more Porous glasses are widely used in microelectronics as inter-metal dielectrics with low dielectric constant (so called low-k dielectrics). At the same time copper is used as a metal because of its low resistivity. Combination of Cu and low-k requires a barrier to prevent Cu diffusion into a low-k dielectric. Integrity of such a barrier becomes an issue when porous glass is used as a low-k dielectric. The barrier should be as thin as possible and fully dense at the same time. Using solvent (toluene) penetration through a barrier [tantalum nitride in our case, which is non-stoichiometric, hence denoted as Ta(N)] and adsorption in porous glass as a barrier integrity probe we show that barrier integrity depends not only on porous structure of the glass, but also on its chemical composition (namely on carbon content). Glasses with high carbon content are easier to seal with Ta(N) barrier. With help of Monte Carlo simulations, we speculate that different chemical composition of the porous glass results in different surface diffusion during barrier deposition. Different surface diffusion, in turn, results in different integrity of the porous barrier.

We review the latest studies that address the fundamental understanding of low-k dielectric elect... more We review the latest studies that address the fundamental understanding of low-k dielectric electrical properties and reliability. We focus on the results discussing the nature of process induced defects, leakage currents and breakdown behavior, as they are important factors to reveal material modification and damage. Issues related to the use of porogen based PECVD techniques during dielectric deposition are discussed, where we focus on the selection of matrix and porogen precursors and on the improvements related to post-deposition treatments. During damascene integration, low-k dielectrics are subjected to several processes that induce material damage, where we review recent learning about plasma exposure, barrier deposition and chemical mechanical polishing. In order to have a successful implementation of advanced ultralow-k films in back-end-of-line interconnects, we argue that more research efforts are needed with respect to its material development, integration and reliability and make some proposals for future work.

MRS Proceedings, 2001

KULeuven. ...

Porous organosilicate glasses (OSG) are important low-k candidates for advanced interconnects. Ho... more Porous organosilicate glasses (OSG) are important low-k candidates for advanced interconnects. However, their integration is very challenging because the etch/strip plasmas degrade their properties and reliability. This problem can be reduced by pore stuffing (for instance, by sacrificial polymers [1]) because it reduces penetration of active radicals and VUV light into the film. The pore stuffing by sacrificial organic polymers is interesting but has few challenges, such as its impact on several steps of the patterning and metallization and possible deformation of low-k film during the stuffing and un-stuffing. An alternative approach based on cryogenic low-k etch has recently been developed [2]. The initial plasma reactants and the reaction products can condense in the pores at cryogenic temperature and protect the low-k films against the plasma damage. Most of reaction products condensed in the pores become volatile at room temperature so the problem of their removal has a relati...

MRS Proceedings, 2001

ABSTRACT

Physical Review B, 2000

Low-temperature transport measurements on superconducting film-normal wire-superconducting film ͑... more Low-temperature transport measurements on superconducting film-normal wire-superconducting film ͑SNS͒ junctions fabricated on the basis of thin superconducting polycrystalline PtSi films are reported. Due to the perfectness of SN boundaries in the junctions, zero bias resistance dip related to pair current proximity effect and subharmonic energy gap structure originating from phase coherent multiple Andreev reflections have been observed and studied.

2011 IEEE International Interconnect Technology Conference, 2011

... P. Verdonck, A. Delabie, J. Swerts, L. Farrell, MR Baklanov, H. Tielens, E. Van Besien, J. Wi... more ... P. Verdonck, A. Delabie, J. Swerts, L. Farrell, MR Baklanov, H. Tielens, E. Van Besien, J. Witters, L. Nyns, S. Van Elshocht ... More accurate calculations of the depth and profile of deposited film have been done using Monte-Carlo simulations. ...

2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings, 2006

Degradation of porous low dielectric constant materials during their exposure in etch and strip p... more Degradation of porous low dielectric constant materials during their exposure in etch and strip plasmas is analyzed from point of view of surface chemistry and recombination of active radicals. Although the degree of damage during the etching can be significantly reduced, the damage in O 2 and H 2 based strip/cleaning plasma are more challenging. The plasma damage mechanisms are the main subject of this discussion. It is demonstrated why the degree of damage can be reduced using He and H 2 based plasmas at elevated processing temperature.

Semiconductor Science and Technology, 2014

A low-temperature multifrequency electron spin resonance (ESR) study has been carried out on Cz-(... more A low-temperature multifrequency electron spin resonance (ESR) study has been carried out on Cz-(110)Si/insulator structures with organosilicate films of low dielectric constant κ grown at 300°C using the plasma-enhanced chemical vapor deposition method (PECVD). After subjection to a short-term UV-irradiation-assisted thermal curing treatment at 430°C to remove the organic component from the low-κ film and obtain optimal porosity, the NL8 ESR spectrum of C 2v symmetry is observed, characterized by g 1 (//[100] = 1.999 83(8), g 2 (//[011] = 1.992 74(8), g 3 = (//[1 10]) = 2.001 15(8). Based on previous insight, this reveals the generation in the c-Si substrate of singly ionized thermal double donor (TDD) defects with a core containing oxygen atoms. Remarkably, the generation is found to be highly nonuniform, and the defect density depth profile shows an exponential-like decay (decay length ∼3.8 μm) from the oxide/Si interface inward the Si substrate, thus exposing the defect formation as an interface-administered effect. Upon analysis, the strain induced by interfacial stress in the c-Si beneath the interface is suggested as the major driving component in the enhancement of TDD formation during thermal treatment, suggesting that substantial stress is involved with PECVD organosilicate low-κ glasses. The result represents a different and affirmative illustration of the influence of strain on TDD formation. Based on the principal g values, the observed TDD is closest to the NL8 1 type, the one formed first in bulk c-Si through oxygen agglomeration during short-term thermal treatment.

2012 IEEE International Interconnect Technology Conference, 2012

ABSTRACT In this work we integrate an advanced k=2.3 spin-on polymer at 40nm ½ pitch. K-value res... more ABSTRACT In this work we integrate an advanced k=2.3 spin-on polymer at 40nm ½ pitch. K-value restoration techniques are investigated and complete k-value restoration is demonstrated using an in-situ HeH2 plasma. An EUV compatible stack and a dielectric dual hard mask scheme is developed to pattern trenches with good uniformity and low litho-etch bias. The impact of scaling the dielectric spacing and of direct CMP on time dependent dielectric breakdown is also studied.

In Atomic Layer Deposition (ALD), initial film growth depends on the chemical nature of the subst... more In Atomic Layer Deposition (ALD), initial film growth depends on the chemical nature of the substrate. Knowledge of the initial growth kinetics of ALD layers on different surface modified porous substrates is important, especially when ultrathin films of a few nanometers thick are needed [1]. The low-k community, for example, could use these insights for effective pore sealing of low-k materials [2]. By enhancing ALD growth in the near surface region as compared to the bulk part of a porous layer, the pores could be sealed off while maintaining porosity in the bulk. In this study three types of porous low-k (k=2.0, SiCOH [3]) films are used: a pristine containing Si-CH 3 surface groups, an O 2 plasma treated film containing Si-OH surface groups throughout the entire layer, and a H 2 /He plasma treated film where Si-OH groups were introduced only in the near-surface region. Deposition of TiO 2 was done in a low-vacuum home-built ALD reactor using tetrakis(dimethylamino) titanium (TDM...

MRS Proceedings, 2006

ABSTRACT Spin-on pure-silica-zeolite MFI films consist of zeolite nanocrystals embedded in a comp... more ABSTRACT Spin-on pure-silica-zeolite MFI films consist of zeolite nanocrystals embedded in a compacted silica matrix of zeolite primary nanoparticles. They appear to be promising as a low-k material due to their good mechanical properties and high microporosity, parallel to their intrinsic low k-value. Results are promising but the implementation of this material is still far away. To contribute to the implementation we present a study on the final film properties depending on the zeolite MFI nanocrystal size. Different techniques are used for the characterization: Dynamic Light Scattering, X-ray diffraction, Scanning Electron Microscopy, Nitrogen adsorption, EllipsoPorosimetry using toluene and NanoIndentation. The results show a clear dependence of the film properties on the nanocrystal size. Clearly, smaller nanocrystals provide better homogeneity, smaller pore size and higher mechanical properties. However, due to the hydrophilicity of the silica matrix lower k-values are only obtained for larger zeolite nanocrystals which provide with higher crystallinity in the films.

Materials Science in Semiconductor Processing, 1998

ABSTRACT