单电子晶体管(SET)可用作超灵敏电荷计,将SET集成到原子力扫描探针上,可得到对被测样品的表面形貌和电荷空间分布扫描成像。介绍了一种硅基台阶型原子力扫描探针与SET的集成方案。一对共漏极的SET集成在台阶型针尖上,台阶型的针尖和静电探针的设计避免了SET的刻蚀损伤。通过SET和静电探针的电容耦合来实现电荷探测。将扫描探针与石英音叉进行组装,在8 K低温下成功实现了间距2μm金属光栅10°倾角的形貌扫描,并获得形貌图,针尖上的SET具有良好的库仑阻塞效应和单电子隧穿特性。
Abstract: The single electron transistor (SET) can be used as a ultra-sensitive charge detector. By the integration of the SET with the atomic-force scanning probe, the scanning images of the surface morphology and charge spatial distribution for the measured sample were obtained. An integration scheme of the silicon-based step-typed atomic force scanning probe and SET was intro- duced. A pair of common drain SETs were integrated on the step-typed probe tip. The designs of the step-shaped probe tip and electrostatic probe can prevent the damage of SET during the etching process. The charge detection was realized by capacitive coupling of the SET and electrostatic probe. The scanning probe and quartz tuning fork were assembled to successfully achieve the morphological scanning image of the metal gratings with 2 μm gap at 10° inclination under 8 K low temperature. The SET on the probe has a good eoulomb bloekade effect and single electron tunneling characteristics.