氢氧化钾溶液腐蚀硅尖具有易于实现、设备简单、优异的纵向腐蚀均匀性等优点,但腐蚀均匀性差、纵向和横向腐蚀速率之比低、针形为不对称的八棱锥。通过在KOH溶液中添加过饱和的碘单质(I2),显著减小了快腐蚀面的削角速率,在较小的掩膜下腐蚀出高的硅尖。更为重要的是该腐蚀液腐蚀的硅尖异于常规的不对称八棱锥,而是一种半锥角很小的“火箭尖”形状,因此可望获得更好的扫描特性和隧道效应。 Potassium hydroxide solution etching silicon tip is easy to implement, simple equipment, excellent vertical corrosion uniformity, etc., but poor corrosion uniformity, the ratio of vertical and horizontal corrosion rate is low, the needle is asymmetric octagonal pyramid. By adding supersaturated iodine (I2) to the KOH solution, the rate of chamfering on the rapidly etched surface is significantly reduced, and the high silicon tip is etched under the smaller mask. More importantly, the etchant erodes the silicon tip distinctly from the conventional asymmetric octagonal pyramid, but rather a “rocket point” shape with a small semi-cone angle so that better scanning characteristics and tunneling are expected effect.