Skip to main content Accessibility help
×
Home
Hostname: page-component-7ccbd9845f-ktfbs Total loading time: 0.228 Render date: 2023-02-01T20:33:27.599Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true

BCl3/N2 Plasma for Advanced non-Si Gate Patterning

Published online by Cambridge University Press:  01 February 2011

Denis Shamiryan
Affiliation:
shamir@imec.be, IMEC, AMPS, Kapeldreef 75, Leuven, N/A, 3001, Belgium, +3216288029, +32281214
Vasile Paraschiv
Affiliation:
parasch@imec.be, IMEC, AMPS, Kapeldreef 75, Leuven, N/A, 3001, Belgium
Salvador Eslava-Fernandez
Affiliation:
eslava@imec.be, IMEC, AMPS, Kapeldreef 75, Leuven, N/A, 3001, Belgium
Marc Demand
Affiliation:
demandm@imec.be, IMEC, AMPS, Kapeldreef 75, Leuven, N/A, 3001, Belgium
Mikhail Baklanov
Affiliation:
baklanov@imec.be, IMEC, AMPS, Kapeldreef 75, Leuven, N/A, 3001, Belgium
Werner Boullart
Affiliation:
boullart@imec.be, IMEC, AMPS, Kapeldreef 75, Leuven, N/A, 3001, Belgium
Get access

Abstract

As conventional materials in CMOS manufacturing, Si as a gate material and SiO2 as a gate dielectric, approach their performance limit, the search for new materials becomes key point. Patterning of the new stacks containing these materials require both new plasma etch chemistries and new approaches.

We propose a BCl3/N2 based plasma mixture for the advanced gate patterning (in this case pure Ge gates and TaN metal gates). There are three reasons to select this combination:

a) The gas mixture generates Cl* species able to etch a diversity of materials, b) it is selective towards Si due to formation of passivating Si-B bonds and c) it improves profile control possibly by formation of a passivating BN-like film on feature side walls. It was found that BCl3 in presence of N2 results in a film deposition if no bias is applied to the substrate (i.e. there is no ion bombardment). The film is hexagonal BN-like since the characteristic peaks corresponding to the in-plane B-N and out-of-plane B-N-B bonds were found in FTIR spectra. The composition of the film surface as found by XPS is B, N and O (as no O2 is present in the plasma it may be a result of oxidation in the atmosphere), the amount of Cl is approx. 1%. The film is soluble in water that makes its removal easy. The deposition rate can be as high as 300 nm/min depending on plasma power, pressure, flow rates and BCl3 to N2 ratio.

We propose to use the BCl3/N2 mixture to etch materials too sensitive to Cl-based plasma. Pure BCl3 plasma might distort gate profiles, as materials are etched in a lateral direction as well, this is the case, e.g. for pure Ge gates. Addition of small amount of nitrogen (5% to 10%) to the BCl3 plasma preserves the vertical profile, apparently by the formation of a passivating BN-like layer on the vertical surfaces where there is no ion bombardment. Too high nitrogen concentration results in positively sloped gate profile or even in the etch stop that could be attributed to the too high deposition rate that exceeds the etch rate. All experiments have been performed in Lam Versys 2300 etch chamber.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Sha, L. and Chang, J. P., J. Vac. Sci. Technol. A, 22, 88 (2004)CrossRefGoogle Scholar
2 Kim, D.-P., Yeo, J.-W., and Kim, C.-I., Thin Solid Films, 459, 122 (2004)CrossRefGoogle Scholar
3 Kim, H.-K., Bae, J. W., Kim, T.-K., Kim, K.-K., Seong, T.-Y., and Adesida, I., J. Vac. Soc. B, 21, 1273 (2003)CrossRefGoogle Scholar
4 Pelhos, K., Donnely, V. M., Kornbilt, A., Green, M. L., Dover, R. B. Van, Manchanda, L., Hu, Y., Morris, M., and Bower, E., J. Vac. Sci. Technol. A, 19, 1361 (2001)CrossRefGoogle Scholar
5 Tai, T., Sugiyama, T., and Sugino, T., Diamond. Relat. Mater., 12, 1117 (2003)CrossRefGoogle Scholar
6 Sugino, T. and Tai, T., Jpn. J. Appl. Phys., 39, L1101 (2000)CrossRefGoogle Scholar
7 Nordheden, K. J., and Sia, J. F., J. Appl. Phys., 94, 2199 (2003)CrossRefGoogle Scholar
8 CRC handbook of Chemistry and Physics, 85th ed. by Lide, D. R., CRC press (2004), p.447 Google Scholar

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

BCl3/N2 Plasma for Advanced non-Si Gate Patterning
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

BCl3/N2 Plasma for Advanced non-Si Gate Patterning
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

BCl3/N2 Plasma for Advanced non-Si Gate Patterning
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *