Organosilane Self-Assembled Thin Resist Films for Nanoprocessing

1)基于气相自组装的超薄抗蚀剂薄膜的制备采用化学气相沉积法制备了有机硅烷自组装单分子膜。在形成SAM之前，使用真空紫外光产生的氧自由基对衬底进行光化学清洗。自组装膜是在气相中形成的。这种方法在涂布和漂洗时都不需要溶剂。SAM抗蚀剂的厚度可以控制在0.2-2.0 nm的范围内。2)SAM抗蚀剂的化学电阻率为了阐明自组装膜可用作腐蚀掩膜，研究了自组装膜在氢氟酸中的湿法腐蚀和油炸腐蚀的化学阻性。尽管自组装膜的厚度小于2 nm，但已发现其具有良好的耐蚀刻蚀性能。3)成功地将小于2 nm的自组装硅烷基自组装膜用于…光刻更适用于真空紫外光刻胶和扫描探针光刻胶。通过光解将光掩模的图像打印在SAM上。另一方面，由于其在AFM探针尖端下局部诱导的电化学降解，在SAM上写入了AFM探针扫描图案。这些微米或纳米级的图形可以通过湿法化学腐蚀或干法等离子体腐蚀转移到硅衬底上。目前，我们分别采用光刻和扫描探针光刻的方法制作了宽度最小为2000 nm和20 nm的特征。此外，我们还演示了基于电流注入AFM光刻的绝缘体纳米结构。采用了具有导电性的多层抗蚀剂薄膜。该抗蚀剂由a-Si、其光化学氧化物和SAM三层膜组成，厚度分别为20、2和2 nm。原子力显微镜首先在SAM中定义了纳米尺度的图案。然后通过两步抗蚀剂显影工艺将这些图案转移到a-Si层中。最后，利用研制的抗蚀剂作为刻蚀掩模，实现了衬底SiO_2的纳米结构。较少

1) Preparation of ultra-thin resist films based on vapor phase self-assemblyOrganosilane self-assembled monolayers (SAM) have been prepared by a chemical vapor deposition method. Prior to the SAM formation, substrates were photochemically cleaned using vacuum ultra-violet light generated oxygen radicals. The SAMs were formed in vapor phase. This method requires no solvent both for coating and rinsing. Thickness of the SAM-resists could be controlled in the range of 0.2 - 2.0 nm.2) Chemical resistivity of the SAM resistsIn order to elucidate that the SAMs can be used as etching masks, chemical resistivity of the SAMs to wet etching in hydrofluoric acid and fry etching were studied. The SAMs have been found to show excellent resistivities to the etchings, although their thickness were less than 2nm. By using the SAMs mask, 50 nm deep trenches could be fabricated by the plasma etching.3) Lithography using SAM resistAn alkylsilane SMA less than 2 nm in thickness has been successfully appli … More ed to the resist for VUV-photolithography and scanning probe lithography. The image of a photomask was printed on the SAM through its photodecomposition. On the other hand, an AFM-probe scanning pattern was written on the SAM due to its electrochemical degradation locally induced beneath the AFM-probe tip. These micro or nano-scale pattern could be transferred into the Si substrates by wet chemical etching or dry plasma etching. At present, features of minimum width of 2000 nm and 20 nm were fabricated by photolithography and the scanning probe lithography, respectively.In addition, we have demonstrated nanostructuring of insulator based on the current-injecting AFM-lithography. A multilayered resist film with electrical conductivity was employed. This resist consisted of triple layers, that is, a-Si, its photochemical oxide and SAM with thicknesses of 20, 2 and 2 nm, respectively. Nanoscale patterns were first defined by AFM in the SAM. These patterns were then transferred into the a-Si layer through the 2-step resist developing process. Finally, the substrate SiO2 was nanostructured using the developed resist as an etching mask. Less