Fused silica microchannel fabrication with smooth surface and high etching selectivity
Fused silica microchannel fabrication with smooth surface and high etching selectivity
复制标题
DOI：
10.1088/1361-6439/acbe4a
复制
发表时间：
2023-04-01
影响因子：
2.3
通讯作者：
Kitamori, Takehiko
中科院分区：
文献类型：
--
作者：
Morikawa, Kyojiro;Chen, Po-yin;Kitamori, Takehiko
通道制造技术在微流控和纳米流控器件中变得越来越重要。特别是由于玻璃通道具有较高的化学和物理稳定性、较高的光学透明度和易于表面改性等特点，因此人们对用于微流体和纳米流体化学实验的玻璃微流体装置越来越感兴趣。对于玻璃通道的制造，特别是那些具有高长宽比（深度/宽度）的通道，使用金属抗蚀剂的光刻和干蚀刻主要被使用。然而，仍然存在涉及蚀刻通道表面粗糙度和低蚀刻选择性的问题。在本研究中，开发了一种具有高蚀刻选择性的微通道制造方法，可以产生光滑的蚀刻表面。首先，假设光刻和Cr刻蚀过程中残留的Cr颗粒在干刻蚀过程中的干扰是造成刻蚀表面粗糙的原因。介绍了三种不同的干蚀刻工艺来验证这一点。在未去除Cr颗粒的工艺1中，蚀刻表面不平坦，具有1 μ m的尺度粗糙度。在工艺2中，包括清洗过程并进行高功率蚀刻，获得了1 nm尺度粗糙度的光滑表面和0.3 μ m min（-1）的更快蚀刻速率。在这种高功率蚀刻条件下，蚀刻选择性（熔融二氧化硅/铬）相对较低，约为39-43。在工艺3中，采用清洁工艺和低功耗蚀刻，虽然蚀刻速率相对较低，为0.1 μ m min(-1)，但获得了1 nm尺度粗糙度的光滑表面（深度区域的10 nm尺度粗糙度大于40 μ m），并且获得了更高的蚀刻选择性，约为79-84。本研究提出的干刻蚀方法对微流控/纳米流控技术在微通道/纳米通道制造中的应用做出了重大贡献。
Channel fabrication technology has become increasingly important for microfluidic and nanofluidic devices. In particular, glass channels have high chemical and physical stability, high optical transparency, and ease of surface modification, so that there is increasing interest in glass microfluidic devices for chemical experiments in microfluidics and nanofluidics. For the fabrication of glass channels, especially those with a high aspect ratio (depth/width), lithography using a metal resist and dry etching have mainly been used. However, there are still issues involving the surface roughness of the etched channel and the low etching selectivity. In this study, a microchannel fabrication method with high etching selectivity that produces a smooth etched surface was developed. First, interference during dry etching by remaining Cr particles after the photolithography and Cr etching processes was assumed as the cause of the rough etched surface. Three different dry etching processes were introduced to verify this. In process 1 without removal of the Cr particles, the etched surface was not flat and had a 1 mu m scale roughness. In process 2 where a cleaning process was included and high power etching was conducted, a smooth surface with a 1 nm scale roughness and a faster etching rate of 0.3 mu m min(-1) were obtained. For this high-power etching condition, the etching selectivity (fused silica/Cr) was relatively low at approximately 39-43. In process 3 with a cleaning process and low-power etching, although the etching rate was relatively low at 0.1 mu m min(-1), a smooth surface with 1 nm scale roughness (10 nm scale roughness deeper than 40 mu m in the depth region) and a much higher etching selectivity of approximately 79-84 were obtained. The dry etching method presented in this study represents a significant contribution to microfluidics/nanofluidics for microchannel/nanochannel fabrication.