钽薄膜淀积速率与阻挡效果的研究

在硅衬底上用不同淀积速率溅射得到了 60 nm厚钽薄膜作为铜布线工艺中的扩散阻挡层。样品在退火前后 ,用二次离子质谱仪 (SIMS)对钽膜的阻挡效果进行鉴定 ,原子力显微镜 (AFM)分析了钽薄膜的形貌结构。研究发现不同淀积速率制作的钽膜由于其结构的差异对铜硅互扩散有着不同的阻挡效果 ,并提出样品在退火时 ,薄膜晶粒的重结晶过程是导致阻挡层失效的重要因素之一     

ULSI铜多层布线中钽阻挡层CMP抛光液的研究与优化

以高浓度纳米SiO2水溶胶为磨料,H2O2为氧化剂的碱性抛光液,研究了适用于终抛铜/钽的CMP抛光液.通过调节pH值,降低抛光液的氧化,增强有机碱的作用,来降低铜的去除速率并提高钽的去除速率,得到了很好的铜/钽抛光选择性.     

ULSI铜多层布线中钽阻挡层CMP抛光液的研究与优化

以高浓度纳米SiO2水溶胶为磨料,H2O2为氧化剂的碱性抛光液,研究了适用于终抛铜/钽的CMP抛光液.通过调节pH值,降低抛光液的氧化,增强有机碱的作用,来降低铜的去除速率并提高钽的去除速率,得到了很好的铜/钽抛光选择性.     

超薄Ru/TaN双层薄膜作为无籽晶铜互连扩散阻挡层

研究了钌（Ru) /氮化钽（TaN）双层结构对铜的扩散阻挡特性，在Si (100）衬底上用离子束溅射的方法沉积了超薄Ru/TaN以及Cu/Ru/TaN薄膜，在高纯氮气保护下对样品进行快速热退火，用X射线衍射、四探针以及电流-时间测试等表征手段研究了Ru/TaN双层结构薄膜的热稳定性和对铜的扩散阻挡特性. 同时还对Ru/TaN结构上的铜进行了直接电镀. 实验结果表明Ru/TaN双层结构具有优良的热稳定性和扩散阻挡特性,在无籽晶铜互连工艺中有较好的应用前景.     

ULSI多层铜布线钽阻挡层及其CMP抛光液的优化

分析了铜多层布线中阻挡层的选取问题,根据铜钽在氧化剂存在的情况下,抛光速率对pH值的不同变化趋势,提出优化碱性抛光液配比进而改变pH值,以达到铜钽抛光一致性的方法,并进行了相应的实验研究.     

超薄Ru/TaN双层薄膜作为无籽晶铜互连扩散阻挡层

研究了钌(Ru)/氮化钽(TaN)双层结构对铜的扩散阻挡特性,在Si(100)衬底上用离子束溅射的方法沉积了超薄Ru/TaN以及Cu/Ru/TaN薄膜,在高纯氮气保护下对样品进行快速热退火,用X射线衍射、四探针以及电流-时间测试等表征手段研究了Ru/TaN双层结构薄膜的热稳定性和对铜的扩散阻挡特性.同时还对Ru/TaN结构上的铜进行了直接电镀.实验结果表明Ru/TaN双层结构具有优良的热稳定性和扩散阻挡特性,在无籽晶铜互连工艺中有较好的应用前景.     

ULSI铜布线阻挡层Ta CMP及抛光液的研究

ULSI多层铜互连线中,由于Cu与Ta的硬度不同带来抛光速率的差异,使得在CMP过程中各种缺陷如碟形坑缺陷、磨蚀缺陷极易发生。研究分析了H2O2、有机碱对Cu和Ta抛光速率的影响,并进行了不同抛光液配比的试验。实验证明,在温度为30℃、压力0.08 MPa,转速60 r/min、抛光液流量为160 mL/min、抛光液成份为V(H2O2)∶V(有机碱)∶V(活性剂)∶V(螯合剂)=5∶15∶15∶25时,抛光速率一致性较好,能够有效降低碟形坑的出现几率;Cu、Ta的抛光速率均为500 nm/min左右,实现了CMP的全局平坦化。     

集成电路多层铜布线阻挡层CMP技术与材料

以化学机械全局平面化(CMP)动力学过程和机理为基础,在抛光浆料中采用粒径为15～20nm的硅溶胶作为CMP磨料,保证了高的抛光速率(200nm/min),同时可有效降低表面粗糙度,减少损伤层的厚度.     

超薄W-Si-N 作为铜与硅之间的扩散阻挡层

研究了W-Si-N三元化合物对铜的扩散阻挡特性.在Si(100)衬底上用离子束溅射方法淀积W-Si-N,Cu/W-Si-N薄膜,样品经过高纯氮气保护下的快速热退火,用俄歇电子能谱原子深度分布与X射线衍射以及电流-电压特性测试等方法研究了W-Si-N薄层的热稳定性与对铜的阻挡特性.实验分析表明W-Si-N三元化合物具有较佳的热稳定性,在800℃仍保持非晶态,当W-Si-N薄层的厚度仅为6nm时,仍能有效地阻挡铜扩散.     

超薄W-Si-N作为铜与硅之间的扩散阻挡层

研究了W- Si- N三元化合物对铜的扩散阻挡特性.在Si ( 10 0 )衬底上用离子束溅射方法淀积W- Si- N ,Cu/W- Si- N薄膜,样品经过高纯氮气保护下的快速热退火,用俄歇电子能谱原子深度分布与X射线衍射以及电流-电压特性测试等方法研究了W- Si- N薄层的热稳定性与对铜的阻挡特性.实验分析表明W- Si- N三元化合物具有较佳的热稳定性,在80 0℃仍保持非晶态,当W- Si- N薄层的厚度仅为6nm时,仍能有效地阻挡铜扩散     

不同氮氩比制备的W-Si-N薄膜的阻挡特性研究

研究了薄膜沉积条件之一——氮气和氩气流量比对超薄(10nm)W-Si-N薄膜作为铜扩散阻挡层的阻挡特性的影响。用薄层电阻、俄歇电子能谱(AES)、X射线衍射谱(XRD)、电容-电压(C-V)等方法系统研究了氮氩比对W-Si-N、Cu/W-Si-N/Si以及Cu/W-Si-N/SiO2/Si结构的热稳定性、电学稳定性的影响。实验发现,W-Si-N薄膜中氮含量对材料的阻挡特性起重要作用,高的氮氩比使薄膜中氮含量增高,薄膜对Cu的扩散阻挡特性增强。     

Evaluation of DC-sputtered Glassy TaCoN Thin Film for Copper Metallization

The failure mechanism of the TaCoN barrier for copper metallization was examined using films by direct current (dc) magnetron reactive sputtering at various nitrogen flow rates. The as-deposited TaCoN films had a glassy structure and were free from intermetallic compounds. Optimizing the nitrogen flow rate during sputtering maximized the thermal stability of the Si/Ta_66.8Co_11.4N_21.8/Cu metallization system up to an annealing temperature of 750°C when the film was deposited using a nitrogen flow rate of 1 sccm, as revealed by using X-ray diffraction, a scanning electron microscope, a four-point probe and a transmission electron microscope. Structural analysis indicated that the failure mechanisms of the studied Si/TaCoN/Cu stacked films involved the initial dissociation of the barrier layer that was annealed at a specific temperature, and the subsequent formation of diffusion paths along which the copper penetrates through the TaCoN barrier layer to react with underlying Si. The high formation temperature of the Cu₃Si phase demonstrated that the studied film was highly stable, indicating that the TaCoN thin film is highly promising for use as a diffusion barrier for Cu metallization.     

Characteristics of Plasma-Treated Amorphous Ta-Si-C Film as a Diffusion Barrier for Copper Metallization

Ta-Si-C film was prepared by magnetron sputtering, and the thermal stability of the plasma-treated film as a copper diffusion barrier was evaluated. The barrier properties and failure behaviors of the studied films were elucidated using a four-point probe, x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The as-deposited Ta-Si-C film had an amorphous structure, and the structure remained stable at an elevated temperature, allowing the film to be adopted as a barrier to inhibit Cu diffusion. The Cu/Ta₂₆Si₄₁C₃₂/Si stacked structure had a failure temperature of 750°C/1 min when the 5-nm-thick Ta₂₆Si₄₁C₃₂ film was treated by exposure to Ar/H₂ plasma mixture, while the stacked film failed at 800°C/1 min when treated by exposure to Ar/N₂ plasma mixture. Using the Ar/N₂ plasma treatment favorably enhanced the thermal stability of the Ta₂₆Si₄₁C₃₂ thin film as a barrier for Cu interconnections. When the Ta-Si-C film thickness was further reduced to 2 nm, the film retained the barrier effect at 650°C, 700°C, and 750°C for Ta₃₄Si₄₇C₁₈, Ta₃₀Si₄₄C₂₅, and Ta₂₆Si₄₁C₃₂ compositions, respectively.     

以注氮SiO_2作为铜互连技术中的新型阻挡层

采用给 PECVD Si O2 中注入氮的方法 ,形成一薄层氮氧化硅 ,以此作为一种新型的扩散阻挡层 .不同热偏压条件下的 C- V测试结果和 XPS分析结果表明 ,该方法能起到对铜扩散的有效阻挡作用     

Electroless CoWP as a Diffusion Barrier between Electroless Copper and Silicon

In this work, an electroless CoWP film deposited on a silicon substrate as a diffusion barrier for electroless Cu and silicon has been studied. Four different Cu 120 nm/CoWP/Si stacked samples with 30, 60, 75, and 100 nm electroless CoWP films were prepared and annealed in a rapid thermal annealing (RTA) furnace at 300°C to 800°C for 5 min. The failure behavior of the electroless CoWP film in the Cu/CoWP/Si sample and the effect of CoWP film thickness on the diffusion barrier properties have been investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and sheet resistance measurements. The composition of the electroless CoWP films was 89.4 at.% Co, 2.4 at.% W, and 8.2 at.% P, as determined by energy dispersive X-ray spectrometer (EDS). A 30 nm electroless CoWP film can prevent copper penetration up to 500°C, and a 75 nm electroless CoWP film can survive at least up to 600°C. Therefore, increasing the thickness of electroless CoWP films effectively increases the failure temperature of the Cu/CoWP/Si samples. The observations of SEM and TEM show that interdiffusion of the copper and cobalt causes the failure of the electroless CoWP diffusion barriers in Cu/CoWP/Si during thermal annealing.     

Thermal and Electrical Properties of PVD Ru(P) Film as Cu Diffusion Barrier

Thermal and electrical properties of physical vapor deposition (PVD) Ru(P) film deposited on porous ultra low-k (p-ULK) material as Cu diffusion barrier were studied. The phosphorous concentration can be tuned by adjusting Ar to PH₃ ratio of the sputtering gases. The leakage current depends on phosphorous concentration. Higher phosphorous content in Ru film has lower leakage current. No obvious phosphorous content dependence was observed when the amorphous Ru(P) film crystallized. The X-ray diffraction (XRD) graphs and energy dispersive spectrometer’s (EDS) atomic depth profiles show that the Ru(P) film deposited on p-ULK can effectively block Cu diffusion when the sample is subjected to 800 °C 5 min annealing. The phosphorous doped Ru film improves diffusion barrier properties and leakage current performance. The improved Ru(P) barrier capable of direct Cu plating could be a potential candidate for advanced metallization.     

缓冲层对铜催化生长碳管形貌和性能的影响

碳纳米管的生长通常使用Fe,Co,Ni作为催化剂,除此以外的一些过渡元素也能催化裂解生长碳管。其中用铜制备的碳管阈值电场低、发射电流密度大、发射均匀性好等等良好的场发射特性。铜与硅、或金属之间具有很强的的扩散特性,而碳管应用于场发射显示器必然使用玻璃、硅片作为衬底,所以需要一层缓冲层阻挡催化剂铜扩散入衬底。本文使用磁控溅射制备铜薄膜作为催化剂,化学气相沉积方法裂解乙炔生长碳管薄膜形成场发射阴极。并试验W,Ni,Cr和Ti作为铜薄膜的缓冲层,结果表明不同的金属阻挡特性不同,生长后碳管的形貌和特性都有差异。结果表明Ti和W能很好地阻挡铜的扩散,从而使铜催化裂解出附着性好、分布均匀、密度适中、场发射特性良好的碳管薄膜。对于Ni和Cr金属,由于生长的碳管与衬底结合差或者场发射能力差而不适合作铜的缓冲层。