High-Density Nanoetchpit-Array Fabrication on Si Surface Using Ultrathin SiO2Mask
High-Density Nanoetchpit-Array Fabrication on Si Surface Using Ultrathin SiO2Mask
复制标题
使用超薄 SiO2 掩模在硅表面制造高密度纳米蚀刻坑阵列
DOI：
10.1143/jjap.39.5352
复制
发表时间：
2000
影响因子：
1.5
通讯作者：
I. Ohdomari
中科院分区：
文献类型：
--
作者：
Meishoku Koh;Souichi Sawara;T. Goto;Yoshinori Ando;T. Shinada;I. Ohdomari
在Si表面人工制备了密度为1.56T（1012）pit/in ~ 2的纳米蚀坑阵列（NEPAs）。高密度NEPA制作成功的关键是通过利用SiO_2作为Si蚀刻掩模和N_2H_4（肼）溶液作为Si蚀刻剂。NEPAs的制作仅分三个步骤：（1）聚焦电子束（EB）照射到SiO2掩模上，（2）使用HF基溶液的SiO2掩模显影，和（3）使用肼的Si蚀刻。在HF基溶液中EB曝光的SiO2的增强蚀刻现象被应用于图案化SiO2掩模。在初始阶段（显影后为4 nm）厚度为8 nm的薄SiO2层用作Si蚀刻掩模，以抑制在显影期间由于电子的前向散射引起的EB暴露区域的扩展和SiO2蚀刻区域的横向延伸。通过浸渍在肼溶液中，通过4 nm厚的SiO2掩模对Si/SiO2具有极高的蚀刻选择性来蚀刻Si衬底。通过使用这个简单的过程，8 nm直径的NEPAs与20 nm的间距成功地安排在Si表面上。
Nanoetchpit arrays (NEPAs) with a density of 1.56 T(1012)pit/in2 were artificially fabricated on Si surfaces. The key to the success of high-density-NEPA fabrication is through utilization of ultrathin SiO2 layer as an Si etching mask and N2H4 (hydrazine) solution as an Si etchant. The NEPAs were fabricated in only three steps: (1) focused electron-beam (EB) irradiation onto SiO2 mask, (2) SiO2 mask development using an HF-based solution, and (3) Si etching using hydrazine. The enhanced etching phenomenon of EB-exposed SiO2 in an HF-based solution was applied to pattern the SiO2 mask. Thin SiO2 layers with a thickness of 8 nm at the initial stage (4 nm after the development) were used as Si etching mask to suppress both spreading of the EB-exposed region by the forward scattering of the electrons and lateral extension of the SiO2 etching region during the development. Si substrates were etched through 4-nm-thick SiO2 mask by dipping in a hydrazine solution with an extremely high etching selectivity for Si/SiO2. By using this simple process, 8-nm-diameter NEPAs with a 20 nm pitch were successfully arranged on Si surfaces.