• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.4 s.33
• /
• pp.29-35
• /
• 2004

We have deposited the W-N diffusion barrier on Si substrate with $NH_3$ pulse plasma enhanced atomic layer deposition (PPALD) method by using $WF_6$ and $NH_3$ gases. The $WF_6$ gas reacts with Si that the surface corrosion occurs severely, but the $NH_3$ gas incorporated with pulse plasma and $WF_6$ gas are easily deposited W-N thin film without Si surface corrosion. Because the $NH_3$ with pulse plasma can be active species dissociated and chemisorbed on Si. Thus the Si surface are covered and saturated with nitrogen, which are able to deposit the W-N thin film. We also examine the deposition mechanism and the effect of $NH_3$ pulse plasma treatment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.2
• /
• pp.150-155
• /
• 2004

This study attempts to form a TiN barrier layer against Cu diffusion by the easier and more convenient method. In this new approach, Ti was sputter-deposited, and nitrided by heat-treating in the NH$_3$ambient. Sheet resistance of as-deposited Ti was 20 Ω/$\square$, but increased to 195 Ω/$\square$ after the heat-treatment at 30$0^{\circ}C$, and lowered to 120 Ω/$\square$ after the heat-treatment at 50$0^{\circ}C$, and $600^{\circ}C$. AES results for these thin films confirmed that the atomic ratio of Ti and N was close to 1:1 at or above 40$0^{\circ}C$ heat-treatment. However, it was also found that excessive oxygen was contained in the TiN layer. To examine the barrier property against Cu diffusion, 100nm Cu was deposited on the TiN layer and then annealed at 40$0^{\circ}C$ for 40 min.. Cu remained at the surface without diffusing into the Si layer.

• Journal of the Korean Magnetics Society
• /
• v.16 no.1
• /
• pp.75-78
• /
• 2006

In case of contacts between semiconductor and metal in semiconductor circuits, they become unstable because of thermal budget. To prevent these problems, we use diffusion barrier that has a good thermal stability between metal and semiconductor. So we consider the diffusion barrier to prevent the increase of contact resistance between the interfaces of metals and semiconductors, and the increase of resistance and the reaction between the interfaces. In this paper we deposited tungsten boron carbon nitride (W-B-C-N) thin film on silicon substrate. The impurities of the $1000\;{\AA}-thick$ W-B-C-N thin films provide stuffing effect for preventing the inter-diffusion between metal thin films $(Cu-2000\;{\AA})$ and silicon during the high temperature $(700\~1000^{\circ}C)$ annealing process.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.169-169
• /
• 2000

최근 반도체 소자의 초고집적화 현상에 따라 기존의 Al-base 합금에 대한 한계에 달하면서 그에 대한 대체 물질로 Cu가 관심을 모으게 되었고 그럼으로써 Cu metallization을 위한 많은 연구가 진행되어 왔다. Cu는 Al-base 합금계보다 비저항이 낮고, 녹는점이 높으며, 또한 electromigration 특성이 뛰어난 것으로 알려져 있다. 공학적인 면에서 이미 이들 계에 대한 adhesion 및 전기적 특성에 대한 많은 연구가 있어왔지만, 이들 특성 변화에 대한 물리적 의미를 제공할 만한 기초 자료들이 부족한 상태이다. 본 연구에서는 부도체인 polyimide 박막과 diffusion barrier인 TiN 박막위에서의 Cu 박막성장에 따르는 interface chemical reaction의 변화를 XPS를 이용하여 관찰함으로서 이들 계에 있어서의 adhesion과의 관계를 조사하였다. 그리고 XPS를 이용한 modified surface accumulation method를 적용시켜 TiN diffusion barrier를 통한 Cu의 grain boundary diffusion 상수들을 측정하였다. Cu/TiN system의 경우에는 interface chemical reaction이 일어나지 않았지만 Cu/polymide system에 있어서는 boundary diffusivity는 특히 40$0^{\circ}C$에서 $650^{\circ}C$ 영역에서, Db=60$\times$10-11exp[-0.29/(kBT)]cm2/sec 이었다.

• Macromolecular Research
• /
• v.12 no.1
• /
• pp.26-31
• /
• 2004

Using gravimetry, we have studied the diffusion of water into sulfonated polystyrene ionomers. Diffusion coefficients were calculated from Fick's equation. The water sorption was found to be dependent on the ion content (3.6-11 mol％) and the nature of the cation (H, Na, Li, or Zn). The sorption kinetics indicates a slight deviation from Fickian behavior. We used the analytical solution of Fick's equation to evaluate the concentration profiles, which are in good agreement with the experimental results.

• Journal of the Microelectronics and Packaging Society
• /
• v.16 no.3
• /
• pp.19-24
• /
• 2009

Formation of an adhesion/barrier layer and a seed layer by sputtering techniques followed by electroplating has been one of the most widely used methods for the filling of through-Si via (TSV) with high aspect ratio for 3-D packaging. In this research, the adhesion and diffusion-barrier properties of the $TaN_x$ film deposited by reactive sputtering were investigated. The adhesion strength between Cu film and $SiO_2$/Si substrate was quantitatively measured by $180^{\circ}$ peel test and topple test as a function of the composition of the adhesive $TaN_x$ film. As the nitrogen content increased in the adhesive $TaN_x$ film, the adhesion strength between Cu and $SiO_2$/Si substrate increased, which was attributed to the increased formation of interfacial compound layer with the nitrogen flow rate. We also examined the diffusion-barrier properties of the $TaN_x$ films against Cu diffusion and found that it was improved with increasing nitrogen content in the $TaN_x$ film up to N/Ta ratio of 1.4.

• Journal of the Semiconductor & Display Technology
• /
• v.2 no.2
• /
• pp.5-8
• /
• 2003

In this study, as Cu diffusion barrier, tantalum nitrides were successfully deposited on Si(100) substrate and $SiO_2$ by plasma assisted atomic layer deposition(PAALD) and thermal ALD, using pentakis (ethylmethlyamino) tantalum (PEMAT) and NH$_3$ as precursors. The TaN films were deposited at $250^{\circ}C$ by both method. The growth rates of TaN films were 0.8${\AA}$/cycle for PAALD and 0.75${\AA}$/cycle for thermal ALD. TaN films by PAALD showed good surface morphology and excellent step coverage for the trench with an aspect ratio of h/w -1.8:0.12 mm but TaN films by thermal ALD showed bad step coverage for the same trench. The density for PAALD TaN was 11g/cmand one for thermal ALD TaN was 8.3g/$cm^3$. TaN films had 3 atomic % carbon impurity and 4 atomic % oxygen impurity for PAALD and 12 atomic % carbon impurity and 9 atomic % oxygen impurity for thermal ALD. The barrier failure for Cu(200 nm)/TaN(10 nm)/$SiO_2$(85 nm)/ Si structure was shown at temperature above $700^{\circ}C$ by XRD, Cu etch pit analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.123-124
• /
• 2005

We investigated the effect of a Ta/TaN Cu diffusion barrier existence on the reliability and the electrical performance of Cu dual-damascene interconnects. A high EM performance in Cu dual-damascene structure was observed the BCV(barrier contact via) interconnect structure to remain Ta/TaN barrier layer. Via resistance was decreased DCV interconnect structure by bottomless process. This structure considers that DCV interconnect structure has lower activation energy and higher current density than BCV interconnect structure. The EM failures by BCV via structure were formed at via hole, but DCV via structure was formed EM fail at the D2 line. In order to improve the EM characteristic of DCV interconnect structure by bottomless process, after Ta/TaN diffusion barrier layer in via bottom is removed by Ar+ resputtering process, it is desirable that Ta thickness is thickly made by Ta flash process.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.18 no.4
• /
• pp.439-455
• /
• 2020

Numerical model was developed that simulates radionuclide (3H and 14C) transport modeling at the 2nd phase facility at the Wolsong LILW Disposal Center. Four scenarios were simulated with different assumptions about the integrity of the components of the barrier system. For the design case, the multi-barrier system was shown to be effective in diverting infiltration water around the vaults containing radioactive waste. Nevertheless, the volatile radionuclide 14C migrates outside the containment system and through the unsaturated zone, driven by gas diffusion. 3H is largely contained within the vaults where it decays, with small amounts being flushed out in the liquid state. Various scenarios were examined in which the integrity of the cover barrier system or that of the concrete were compromised. In the absence of any engineered barriers, 3H is washed out to the water table within the first 20 years. The release of 14C by gas diffusion is suppressed if percolation fluxes through the facility are high after a cover failure. However, the high fluxes lead to advective transport of 14C dissolved in the liquid state. The concrete container is an effective barrier, with approximately the same effectiveness as the cover.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2005.11a
• /
• pp.132-133
• /
• 2005