Stress-induced current in nitride and oxidized nitride thin films

Mazumder, M.K.; Kobayashi, Kenzo; Mitsuhashi, J.; Koyama, Hiroshi

doi:10.1109/16.337458

Cited by 15 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In finding alternative dielectric materials, silicon nitride films, such as oxynitride, 2,3) reoxidized nitride, 4) and jetvapor-deposited (JVD) nitride films, [5][6][7] have been extensively studied because of their higher permittivity (k = 7.2) and more effective suppression of Boron penetration 8) into the substrate than silicon oxide films. However, thick silicon nitride films are known to have a high leakage current density, which is strongly related to its poor nitride film quality, e.g., too many charge traps and high interface state density.…”

Section: Introductionmentioning

confidence: 99%

“…15) It was also reported that when oxide was grown on the nitride, the hole flow through the nitride can be blocked by the oxide and hence the total gate leakage current is reduced. 4) In this work, we present a novel method of reoxidizing * E-mail address: hwu@cc.ee.ntu.edu.tw the Si 3 N 4 film. Room-temperature anodic reoxidation in deionized (DI) water was used to reoxidize Si 3 N 4 for the first time.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of Anodization to Reoxidize Silicon Nitride Film

Lin

Hwu

2001

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Anodic reoxidation of ultrathin Si 3 N 4 film in deionized (DI) water followed by rapid thermal annealing (RTA) in N 2 (ANO) was for the first time studied in this work. The Si 3 N 4 film directly reoxidized in O 2 by RTA (O 2 RTA) was used for comparison. It was found that the reoxidation process could significantly improve the characteristics of chemical-vapor-deposited (CVD) Si 3 N 4 in terms of both the interface and bulk qualities. The ANO samples show lower leakage current, lower interface trap and bulk trap densities, and higher breakdown field than O 2 RTA of the same equivalent oxide thickness (EOT). The better electrical characteristics of ANO are due to more oxygen atoms incorporated into the Si 3 N 4 films during the anodic reoxidation.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Application of Anodization to Reoxidize Silicon Nitride Film

Lin

Hwu

2001

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…8 When oxide is grown on the surface or incorporated into the nitride, the hole-flow current may be suppressed by the oxide, because the holes face a much higher barrier of SiO 2 (⌽ Bh ϭ 4.4 eV͒ than Si 3 N 4 (⌽ Bh ϭ 1.8 eV͒. 9 Accordingly, the total gate leakage current would be quenched after oxidation.…”

mentioning

confidence: 99%

Quality Improvement in LPCVD Silicon Nitrides by Anodic and Rapid Thermal Oxidations

Lin

Hwu

2004

Electrochem. Solid-State Lett.

View full text Add to dashboard Cite

Low-pressure chemical vapor deposition ͑LPCVD͒ Si 3 N 4 quality presents a dramatic improvement after oxidation. Both liquidphase anodic oxidation and rapid thermal oxidation were studied in this work. After oxidation, ''SiO 2 ''-like layers grown on the surface, and oxygen incorporated into the Si 3 N 4 layer were observed. The nonstoichiometric bonding, i.e., Si 2 vN, Si dangling bonds, and crystalline Si were oxidized into Si 2 vNuO or SiO 2 , and the stoichiometric Si 3 wN bonding maintained a higher-k property. In addition, more oxygen replacement of the imperfect Si-N bonds after anodic oxidation contributed to better improvement in suppressing gate leakage current.For the shrinkage of metal-oxide-semiconductor field-effect transistors ͑MOSFETs͒, device-grade ultrathin SiO 2 is necessary to meet the integrated circuit requirement. However, the increasing problems with boron penetration through ultrathin oxide and exponentially increased direct tunneling ͑DT͒ current dictate the replacement of the prospective dielectrics. 1 Alternative material with higher permittivity is therefore considered because of the greater physical thickness under the same capacitance. Among these high-k materials, silicon-based Si 3 N 4 has been studied extensively, because of its high permittivity (k ϭ 6 -8, depends on stoichiometry͒, high processes compatibility, and good capability for suppressing boron penetration. 2 To obtain a stoichiometric Si 3 N 4 film, the nitriderelated technologies such as chemical vapor deposition ͑CVD͒ nitride, 3 jet-vapor-deposited ͑JVD͒ nitride, 4 atomic-layer-deposition ͑ALD͒, 5 and nitrided-SiO 2 , i.e., oxynitride, 6 have been studied extensively.At the same time, Si 3 N 4 grown by low-pressure chemical vapor deposition ͑LPCVD͒ is used to mask the active region or store the memory charges. CVD nitride exhibits a high throughput merit in batch processes. However, interactions of SiCl 2 H 2 and NH 3 tend to form silicon-rich nitride films, a great amount of traps and unbounded dangling bonds are present. Also, the extended crystalline silicon would induce extra leaky gate current that is unfavorable for transistor gate insulator. From a previous report, oxidation of CVD nitride is significant in enhancing dielectric quality. 7 Reaction between oxidant and CVD nitride plays a major role to compensate the imperfect bonding and reduce the traps. In addition, due to the barrier height difference under migration, electrons and holes were reported to be the dominant conduction carriers in SiO 2 and Si 3 N 4 , respectively. 8 When oxide is grown on the surface or incorporated into the nitride, the hole-flow current may be suppressed by the oxide, because the holes face a much higher barrier of SiO 2 (⌽ Bh ϭ 4.4 eV͒ than Si 3 N 4 (⌽ Bh ϭ 1.8 eV͒. 9 Accordingly, the total gate leakage current would be quenched after oxidation.From our studies, anodic oxidation exhibits the merits of low thermal budget and better thickness uniformity than thermal oxidation. 10 In this work, liquid-phase anodic oxidation and ...

show abstract

“…Much of these published reliability results were obtained from planar structures with the bottom-oxide grown on doped poly-Si, which is known to have microstructure and morphology problems (43. The films reported previously were much thicker (8.0-10.0 nm) than the data presented in this work (4)(5)(6)(7). For the first time, this paper describes extensive results for intrinsic breakdown characteristics of reoxidized nitride (NO) dielectric films using deep-trench capacitors with the oxide equivalent thickness (T,) down to 3.9 nm.…”

Section: Introductionmentioning

confidence: 82%

Thickness and polarity dependence of intrinsic breakdown of ultra-thin reoxidized-nitride for DRAM technology applications

Hwang²,

Vollertsen³

et al.

International Electron Devices Meeting. IEDM Technical Digest

View full text Add to dashboard Cite

This paper discusses the charge-trapping and intrinsic breakdown characteristics of ultra-thin reoxidized nitride with deeptrench capacitor structures for a range of thickness, voltages, and temperatures. Strong polarity dependence of charge-trapping and time-dependent dielectric breakdown (TDDB) is reported. For the first time, a physical model is proposed to relate the asymmetric charge injection and trapping to this intrinsic breakdown characteristic in thin reoxidized nitride. The thickness dependence of TDDB is also investigated and used for a reliability projection of the oxide equivalent thickness down to 2.9 nm.

show abstract

Stress-induced current in nitride and oxidized nitride thin films

Cited by 15 publications

References 29 publications

Application of Anodization to Reoxidize Silicon Nitride Film

Application of Anodization to Reoxidize Silicon Nitride Film

Quality Improvement in LPCVD Silicon Nitrides by Anodic and Rapid Thermal Oxidations

Thickness and polarity dependence of intrinsic breakdown of ultra-thin reoxidized-nitride for DRAM technology applications

Contact Info

Product

Resources

About