Enabling 3X nm DRAM: Record low leakage 0.4 nm EOT MIM capacitors with novel stack engineering

Pawlak, Małgorzata; Popovici, M.; Swerts, Johan; Tomida, Kazuyuki; Kim, Min‐Soo; Kaczer, B.; Opsomer, Karl; Schaekers, Marc; Favia, P.; Bender, Hugo; Vrancken, C.; Govoreanu, B.; Demeurisse, C.; Wang, Wan-Chih; Afanasʼev, Valeri; Debusschere, I.; Altimime, L.; Kittl, Jorge

doi:10.1109/iedm.2010.5703344

Cited by 19 publications

(30 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The optimization of the dielectrics stacks for the trenched DRAMs was reported in another study. 33 For the higher voltage regime a bias voltage of 3 V was chosen. This is the highest voltage at which all investigated dielectrics show leakage currents low enough for reliable capacitance measurements.…”

Section: Resultsmentioning

confidence: 99%

Dielectric Material Options for Integrated Capacitors

Ruhl

Lehnert

Lukosius³

et al. 2014

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication Citation for published version (APA):Ruhl, G., Lehnert, W., Lukosius, M., Wenger, C., Baristiran Kaynak, C., Blomberg, T., ... Rushworth, S. A. (2014). Dielectric material options for integrated capacitors. ECS Journal of Solid State Science and Technology, 3(8), N120-N125. DOI: 10.1149/2.0101408jss General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Download date: 11. May. 2018 Science and Technology, 3 (8) N120-N125 (2014) 2162-8769/2014/3(8) Future MIM capacitor generations will require significantly increased specific capacitances by utilization of high-k dielectric materials. In order to achieve high capacitance per chip area, these dielectrics have to be deposited in three-dimensional capacitor structures by ALD or AVD (atomic vapor deposition) process techniques. In this study eight dielectric materials, which can be deposited by these techniques and exhibit the potential to reach k-values of over 50 were identified, prepared and characterized as single films and stacked film systems. To primarily focus on a material comparison, preliminary processes were used for film deposition on planar test devices. Measuring leakage current density versus the dielectric constant k shows that at low voltages (≤1 V) dielectrics with k-values up to 100 satisfy the typical leakage current density specification of <10 −7 A/cm 2 for MIM capacitors. At higher voltages (3 V) this specification is only fulfilled for dielectrics with k-values below 45. As a consequence, the maximum achievable capacitance gain by introducing high-k dielect...

show abstract

Section: Resultsmentioning

confidence: 99%

Dielectric Material Options for Integrated Capacitors

Ruhl

Lehnert

Lukosius³

et al. 2014

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…20 Recent developments on ALD of STO showed that Sr-rich films have a smaller grain size after annealing resulting in lower leakage current values. 19,21 For these reasons monitoring the stoichiometry and crystallinity of STO films is necessary to tune the processing conditions such that the requirements for the application envisioned are met.…”

mentioning

confidence: 99%

Plasma-Assisted Atomic Layer Deposition of SrTiO₃: Stoichiometry and Crystallinity Studied by Spectroscopic Ellipsometry

Longo

Leick

Roozeboom

et al. 2012

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

Strontium titanate (SrTiO3, STO) films were deposited by plasma-assisted ALD using cyclopentadienyl-based Sr- and Ti-precursors with O2 plasma as the oxidizing agent. Spectroscopic ellipsometry (SE) was employed to determine the thickness and the optical properties of the layers. As determined from Rutherford backscattering spectrometry (RBS), [Sr]/([Sr]+[Ti]) ratios ranging from 0.42 to 0.68 were achieved for 30–40 nm thick films by tuning the [SrO]/[TiO2] ALD cycle ratio. Films deposited at 250°C were amorphous and required post-deposition annealing to crystallize into the ultrahigh-k perovskite structure. The crystallinity of the films after rapid thermal annealing strongly depended on the film composition as observed by X-ray diffraction measurements. Using RBS data for a set of as-deposited samples, an optical constant library was built to determine the film stoichiometry from SE directly for the amorphous as-deposited films. After rapid thermal annealing the crystalline phase could be determined from the position of critical points of the measured dielectric function and the estimation of the stoichiometry was also possible for crystallized layers. These results open up a new way to use SE as a real-time characterization method to monitor and tune the STO film composition and crystallinity.

show abstract

“…13,14 and dielectric properties. [10][11][12][13]18 This example shows the importance of resolving the correct process and temperature window to obtain the desired film properties for the specific application targeted. In recent literature, TEM studies have been published on STO films deposited by ALD and crystallized by rapid thermal annealing (RTA) with the aim of determining the STO microstructure and its relation to electrical properties.…”

mentioning

confidence: 99%

“…[15][16][17] However, Sr-rich layers are to be used in next generation DRAM due to their superior dielectric properties and microstructure leading, amongst others, to lower leakage currents. 10,11 The thermal budget applied during annealing as well as specific parameters such as film composition and thickness are of crucial importance as they determine the crystallization behavior and the consequent final microstructure and electrical properties of the crystallized STO films. Crystallization of the film leads to in-plane and out-of-plane densification of the film.…”

mentioning

confidence: 99%

“…This property combined with a good thermal stability and relatively low crystallization temperature makes STO the dielectric material of choice for next generation dynamic random access memories (DRAM). [10][11][12] STO high-k dielectric films have been deposited by ALD, especially since the application in deep trenches in silicon wafers calls for extremely conformal layers in such 3D structures. As ALD is the preferred technology of choice, the thermal budget used during the deposition needs to be limited to prevent decomposition of the metal-organic precursors typically employed.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Crystallization Study by Transmission Electron Microscopy of SrTiO₃ Thin Films Prepared by Plasma-Assisted ALD

Longo¹,

Roozeboom²,

Kessels³

et al. 2013

ECS Trans.

View full text Add to dashboard Cite

The crystallization behavior of thin strontium titanate (SrTiO3, STO) films with ~15 nm thickness was studied by Transmission Electron Microscopy (TEM). Amorphous STO films with [Sr]/([Sr]+[Ti]) ratio ranging from 0.51 to 0.65 were deposited at 350 {degree sign}C by plasma-assisted ALD and subsequently treated by rapid thermal annealing for crystallization. Different temperatures and annealing durations were employed to fully characterize the crystallization process. TEM analysis evidenced the influence of the STO composition and of the thermal budget applied on the grain size, cracks and void formation. In particular, Sr-rich layers ([Sr]/([Sr]+[Ti] {greater than or equal to} 0.6) showed a finer crystalline structure which was imputed to a higher nucleation probability at the onset of the crystallization process. By tuning the STO composition and the thermal budget of the annealing step it was demonstrated that it is possible to control the microstructure of the crystallized STO layers.

show abstract

Enabling 3X nm DRAM: Record low leakage 0.4 nm EOT MIM capacitors with novel stack engineering

Cited by 19 publications

References 1 publication

Dielectric Material Options for Integrated Capacitors

Dielectric Material Options for Integrated Capacitors

Plasma-Assisted Atomic Layer Deposition of SrTiO₃: Stoichiometry and Crystallinity Studied by Spectroscopic Ellipsometry

Crystallization Study by Transmission Electron Microscopy of SrTiO₃ Thin Films Prepared by Plasma-Assisted ALD

Contact Info

Product

Resources

About

Enabling 3X nm DRAM: Record low leakage 0.4 nm EOT MIM capacitors with novel stack engineering

Cited by 19 publications

References 1 publication

Dielectric Material Options for Integrated Capacitors

Dielectric Material Options for Integrated Capacitors

Plasma-Assisted Atomic Layer Deposition of SrTiO3: Stoichiometry and Crystallinity Studied by Spectroscopic Ellipsometry

Crystallization Study by Transmission Electron Microscopy of SrTiO3 Thin Films Prepared by Plasma-Assisted ALD

Contact Info

Product

Resources

About

Plasma-Assisted Atomic Layer Deposition of SrTiO₃: Stoichiometry and Crystallinity Studied by Spectroscopic Ellipsometry

Crystallization Study by Transmission Electron Microscopy of SrTiO₃ Thin Films Prepared by Plasma-Assisted ALD