• 한국전기전자재료학회논문지
• /
• 제16권12S호
• /
• pp.1181-1186
• /
• 2003

Chemical Mechanical Polishing (CMP) is an essential dielectric planarization in multilayer microelectronic device fabrication. In the CMP process, it is necessary to minimize the extent of surface defect formation while maintaining good planarity and optimal material removal rates. The polishing mechanism of W-CMP process has been reported as the repeated process of passive layer formation by oxidizer and abrasion action by slurry abrasives. Thus, it is important to understand the effect of oxidizer on W passivation layer, in order to obtain higher removal rate (RR) and very low non-uniformity (NU %) during W-CMP process. In this paper, we compared the effects of oxidizer or W-CMP process with three different kind of oxidizers with 5 wt% hydrogen peroxide such as Fe(NO$_3$)$_3$, H$_2$O$_2$, and KIO$_3$. The difference in removal rate and roughness of W in stable and unstable slurries are believed to caused by modification in the mechanical behavior of Al$_2$O$_3$ particles in presence of surfactant stabilizing the slurry.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
• /
• pp.243-246
• /
• 2004

W CMP 공정에서 abrasive 의 size 및 shape 에 따른 CMP 거동에 대해 관찰하였으며, 주요 제거 막질인 W 막질과 stopping layer 로 사용되는 Oxide 막질에 대한 압력(P)과 상대 속도(V) 영향성을 관찰하였다. CMP 제거량이 입자의 size 변화에 의존한다는 기존의 이론과는 달리 응집도(aggregate ratio) 변화가 주요 변수임을 밝혀 내었다. 한편, 각 막질에 대한 P,V 영향성 평가를 통해, 변형된 Prestonian equation 이 abrasive size 및 shape 에 상관없이 W 막질의 제거 거동을 설명하는데 중요한 역할을 수행함을 보였다. 그렇지만, W CMP 공정에서 stopping layer 로 사용되는 oxide 막질의 거동을 설명하는 데에는 어려움이 있었으며, 특히 P,V 에 의한 비선형적 removal rate(RR) 거동발생으로 인해 기존의 이론치와는 많은 차이를 나타내었다. 또한, abrasive size 와 shape 에 따라서도 복잡한 거동을 나타낸다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
• /
• pp.366-367
• /
• 2006

In general, HF chemistry lifts off the particles during scrubbing after polishing and effectively removes particles. It is sometimes impossible to apply HF chemistry on W plug due to the degradation of electrical characteristics of a device. In this paper, a post W CMP cleaning process is proposed to remove residue particles without applying HF chemistry. After W CMP, recessed plugs are created, therefore they easily trap slurry particles during CMP process. These particles in recessed plug are not easy to remove by brush scrubbing when $NH_4OH$ chemistry is used for the cleaning because the brush surface can not reach the recessed area of plugs. Buffing with oxide slurry was followed by W CMP due to its high selectivity to W. The buffing polishes only oxide slightly which creates higher plug profiles than surrounding oxide. Higher profiles make the brush contact much more effectively and result in a similar particle removal efficiency even in $NH_4OH$ cleaning to that in HF brush scrubbing.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
• /
• pp.178-181
• /
• 2002

We studied the characteristics of polishing pad, which can apply W CMP process for global planarization of multilevel interconnection structure. Also we investigated the effects of different sets of polishing pad. The purpose of this experiment is the cost reduction by the increase of pad life time and decrease of cycle time and slurry usage with new pad. Especially we studied the effect of polishing pad for CMP process by this experiment of polishing pad that is consumables material during CMP process. We expecting the increase of process throughput and improvement of device manufacturing yield because we can choose optimum polishing pad through this result.

• 한국전기전자재료학회논문지
• /
• 제17권4호
• /
• pp.378-383
• /
• 2004

Tungsten is widely used as a plug for the multi-level interconnection structures. However, due to the poor adhesive properties of tungsten(W) on SiO$_2$ layer, the Ti/TiN barrier layer is usually deposited onto SiO$_2$ for increasing adhesion ability with W film. Generally, for the W-CMP(chemical mechanical polishing) process, the passivation layer on the tungsten surface during CMP plays an important role. In this paper, the effect of oxidant on the polishing selectivity of W/Ti/TiN layer was investigated. The alumina(A1$_2$O$_3$)-based slurry with $H_2O$$_2$ as the oxidizer was used for CMP applications. As an experimental result, for the case of 5 wt％ oxidizer added, the removal rates were improved and polishing selectivity of 1.4:1 was obtained. It was also found that the CMP characteristics of W and Ti metal layer including surface roughness were strongly dependent on the amounts of $H_2O$$_2$ oxidizer.

• 한국전기전자재료학회논문지
• /
• 제26권12호
• /
• pp.920-923
• /
• 2013

In this paper, the characteristics of a carbon nanotube composite heat sink proposed to replace the advanced Al heat sinks for LED lighting devices were studied. Proposed CMP-PLA heat sink was made by mixing 20~70 wt% carbon nanotube, 20~70 wt% bio-degradable polymer of melt-blended PLA (poly lactic acid) and PBS (poly butylene succinate) and PLA nucleating agents composed of the mixture of soybean oil and biotites, at $150{\sim}220^{\circ}C$ with 1,000~1,500 rpm. Optical and electric characteristics of 7.5 W LED lighting devices using heat sinks with such prepared CMP-PLA were investigated. And, the properties of the heat, which was not released from the CMP-PLA type heat sinks, was also investigated. The color temperature of LED lighting devices using the CMP-PLA heat sinks was 5,956 K, which is x= 0.32 and y= 0.34 in the XY chromaticity, and the color rendering index was 75. The luminous flux and the luminous efficiency of LED lighting devices using the CMP-PLA heat sinks was 540.6 lm and 72.68 lm/W respectively. Measured initial temperature of the heat sinks was $27^{\circ}C$, and their temperature increased as time to be saturated at $52^{\circ}C$ after an hour.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
• /
• pp.147-150
• /
• 2002

In this study, we evaluated the dilute HF Cleaning to reduce residual defects made by W CMP process. But, One point we should focus is It should not effect to metal thin film reliability. The purpose of this test is to verify barrier metal damage during HF cleaning and based on this result we get rid of slurry residue defect which is main defect of W CMP process for the better yield.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
• /
• pp.46-49
• /
• 2003

Chemical mechanical polishing (CMP) is an essential dielectric planarization in multilayer microelectronic device fabrication. In the CMP process it is necessary to minimize the extent of surface defect formation while maintaining good planarity and optimal material removal rates. The polishing mechanism of W-CMP process has been reported as the repeated process of passive layer formation by oxidizer and abrasion action by slurry abrasives. Thus, it is important to understand the effect of oxidizer on W passivation layer, in order to obtain higher removal rate (RR) and very low non-uniformity (NU%) during W-CMP process. In this paper, we compared the effects of oxidizer or W-CMP process with three different kind of oxidizers with 5% hydrogen peroxide such as $Fe(NO_3)_3$, $H_2O_2$, and $KIO_3$. The difference in removal rate and roughness of W in stable and unstable slurries are believed to caused by modification in the mechanical behavior of $Al_3O_3$ particles in presence of surfactant stabilizing the slurry.

• 대한화학회지
• /
• 제47권6호
• /
• pp.608-613
• /
• 2003

Post-Oxide CMP(Chemical-Mechanical Polishing) 결과 실리콘 웨이퍼를 오염 시키고 있는 슬러리 입자의 세정 가능성을 조사하기 위하여DHF(Diluted HF)에 비이온성 계면 활성제인 PAAE(Polyoxyethylene Alkyl Aryl Ether), 비양성자성 용제인 DMSO(Dimethylsulfoxide) 와 초순수의 혼합물인 새로운 세정액을 제조하였다. 세정력을 평가하기 위해서 세정제 내에서 각각 다른 제타 포텐셜을 갖는 실리카($SiO_2$), 알루미나($Al_2O_3$)와 PSL(polystylene latex) 입자를 실리콘 웨이퍼 표면의 산화막에 인위적으로 오염시킨 후 실험에 이용하였다. 초음파하에서 세정액의 성능 평가 결과 본 세정기술은 효과적인 입자의 세정능력과 금속이온에 대한 세정 능력을 나타내고 있음을 확인하였다. 즉 기존의 APM($NH_4OH,\;H_2O_2$와 D.I.W의 혼합물)과 달리 상온에서 세정이 가능하고 세정과정이 단축 되었으며, 낮은 농도의 HF를 사용함으로써 최소의 에칭에 의하여 표면 거칠기를 감소시킬 수 있음을 보여주고 있다. 또한 주요 CMP 금속 배선 물질들에 대한 낮은 부식력으로 기존의 CMP 후 세정공정에 뿐만 아니라 차세대CMP 공정으로 각광 받고 있는 Copper CMP 에 대한 Brush 세정 공정의 보조 세정제로 본 세정제가 적용될 가능성이 있음을 확인하였다.

• 한국전기전자재료학회논문지
• /
• 제13권7호
• /
• pp.568-574
• /
• 2000

We have been optimized tungsten(W) plug CMP(chemical mechanical polishing) characteristics using two different kinds of component of slurry and two different kinds of pad which have different hardness. The comparison of oxide film roughness on around W plug after polishing has been carried out. And W plug recess for consumable sets and dishing effect at dense area according to the rate of over-polishing has been investigated. Also the analysis of residue on surface after cleaning have been performed. As a experimental result we have concluded that the consumable set of slurry A and hard pad was good for W plug CMP process. After decreasing the rate of chemical reaction of silica slurry and adding two step buffering we could reduce the expanding of W plug void however we are still recognizing to need a more development for those kinds of CMP consumables.