Commercialization of a high performance SML series electron beam resist for nano lithography

电子束光刻技术(EBL)可以通过对带有窄电子束的薄膜抗蚀剂进行图案化来制造纳米级结构。然后，图案分别通过剥离(金属化)或蚀刻工艺从该‘掩模’转移到衬底上或进入衬底。EBL现在是纳米技术行业的标准工具，特别是在纳米电子学领域。EBL机器的成本从~GB 100K到超过GB 2M不等(例如，Vistec EBPG+5000)，该行业大致分为两类：运行在30KV及以下的低压机器(便宜)和运行在100KV的高压机器(非常昂贵)。昂贵的高压机的主要优势是它们能够将电子束抗蚀剂图案化成更小的特征，并且比低压系统具有更高的纵横比。曼彻斯特大学开发了一种名为SML系列抗蚀剂的新型电子束抗蚀剂，以在低加速电压下获得大宽高比。如上所述，通常，大长宽比结构只能使用100KV EBL机器来实现。然而，使用中的绝大多数EBL机器都是低电压品种，因此大多数EBL社区无法获得制造高深宽比结构的能力。SML系列抗蚀剂克服了这一问题，使其能够使用低电压机器制造非常高宽高比的结构。

Electron beam lithography (EBL) enables the fabrication of nano-scale structures via the patterning of a thin film resist with a narrow beam of electrons. A pattern is then transferred from this 'mask' onto or into a substrate via lift-off (metallization) or etching processes respectively. EBL is now a standard tool in the nanotechnology industry, and particularly in nanoelectronics. EBL machines can cost anywhere from ~£100K to over £2M (e.g. Vistec EBPG +5000), and the industry is broadly split into two categories: low voltage machines that operate at 30KV and below (cheap), and high voltage machines that operate at 100KV (very expensive). The main advantage of the expensive high voltage machines is that they are capable of patterning an electron beam resist into smaller features, and with higher aspect ratios than the low voltage systems. A new electron beam resist called SML series resist has been developed at the University of Manchester to obtain large aspect ratios using low acceleration voltages. As described above, typically, large aspect ratio structures can only be achieved using 100KV EBL machines. However, the vast majority of EBL machines in use are of the low voltage variety and so the ability to fabricate high aspect ratio structures is not accessible to the majority of the EBL community. The SML series resist overcomes this issue and enables the fabrication of very high aspect ratio structures using low voltage machines.