Conformal Deposition of Dielectric Nanolaminates

研究：在之前由美国国家科学基金会支持的工作中，PI发现了一种快速沉积主要由二氧化硅（二氧化硅）组成的高度适形涂层的工艺。该方法使用交替层沉积（ADL），将两种不同的蒸汽交替提供给表面，以制造纳米级层压的涂层。每一层的形成都具有高度精确的原子级控制厚度、平滑度、一致性和成分。PI提出的理论应该允许他以五种不同的方式扩展这种沉积方法的能力：更低的介电常数。碳掺杂的二氧化硅薄膜将用于降低介电常数(k)。通过对前驱体进行化学改性，将碳引入涂层中。选择性密封孔隙。利用ALD工艺的催化特性，PI计划将碳掺杂的低k材料沉积在超低k电介质表面附近的孔隙中，而不需要在内部孔隙中放置任何材料。该工艺将防止导电材料沉积在超低k介电材料上后发生的漏电。选择性填沟。通过另一种利用ALD工艺的催化特性，PI计划用低k材料填充狭窄沟槽的内部，同时保持相邻的平坦表面没有任何沉积物。更高的增长率。利用他的ALD过程的理论机制，他计划通过合成和测试一种新的化学前体来进一步提高生长速度。光学多滤光片的ALD。ALD工艺具有良好的特性，可以为光学多层滤光片制作优质的低折射率层，甚至可以在透镜或聚焦镜等非平面表面上使用。对于这些滤波器所需的其他材料层的ALD也正在考虑一种方法。广泛影响：五项计划活动中的每一项都可能对微电子和光通信工业的关键需求产生重要影响。这一过程将扩展ALD的独特能力，以制造微电子行业所需的高适形低k绝缘体。在微电子中，为了提供制造互连所需的光滑表面，需要对超低k介电材料的表面孔隙进行选择性密封。选择性沟槽填充将允许填充微电子晶体管之间的隔离沟槽，而无需使用昂贵的化学/机械抛光步骤，通常需要从顶部表面去除多余的二氧化硅。实现更高的沉积速率将使ALD工艺在所有实际应用中更具成本效益。集成光电子、光通信等领域都需要高质量的波长选择滤波器。

Research:In previous work supported by NSF, the PI discovered a process for the rapid deposition of highly conformal coatings consisting mostly of silicon dioxide (silica). The method uses alternating layer deposition (ADL) from two different vapors supplied alternately to a surface to make a coating that is laminated on the nanometer scale. Each layer is formed with a highly precise atomic level of control over thickness, smoothness, conformality and composition.The PI proposes theories that should permit him to extend the capability of this deposition method in five different ways:1. Lower dielectric constant. Carbon-doping of the silica films will be used to lower the dielectric constant (k). Carbon will be introduced into the coating by chemical modification of the precursors.2. Selective sealing of pores. By use of the catalytic character of the ALD process, the PI plans to deposit the carbon-doped low-k material to seal the pores near the surface of the ultra-low-k dielectrics, without placing any material inside interior pores. This process will prevent the electrical leakage that occurs after deposition of electrically conductive materials onto ultra-low-k dielectric materials.3. Selective trench filling. By another use of the catalytic character of the ALD process, the PI plans to fill the insides of narrow trenches with low-k material, while keeping adjacent flat surfaces free of any deposit.4. Higher growth rate. Using his theoretical mechanism for the ALD process, he plans to further increase growth rate by the synthesis and testing of a new chemical precursor.5. ALD of optical multiplayer filters. The ALD process has the right characteristics to make superior low-index layers for optical multi-layer filters, even on non-planar surfaces such as those found on lenses or focusing mirrors. A method is also being considered for ALD of layers of the other material needed for these filters.Broad Impact:Each of the five planned activities could have important impact on critical needs in the microelectronics and optical communications industries:1. This process would extend the unique capabilities of ALD to make highly conformal low-k insulators needed in microelectronics.2. Selective sealing of surface pores on ultra-low-k dielectrics is needed to provide the smooth surfaces needed for making interconnections in microeletronics.3. Selective trench filling would allow the filling of isolated trenches between microelectronic transistors without the use of the expensive chemical/mechanical polishing step normally needed to remove excess silica from the top surface.4. Achievement of still higher deposition rates will make the ALD process more cost-effective for all practical applications.5. Wavelength-selective filters with higher quality are needed in fields such as integrated optics and electronics, and optical communications.