Kundhikanjana Worasom, Lai Keji, Kelly Michael A, Shen Zhi-Xun
Department of Applied Physics and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.
Rev Sci Instrum. 2011 Mar;82(3):033705. doi: 10.1063/1.3554438.
We report the instrumentation and experimental results of a cryogenic scanning microwave impedance microscope. The microwave probe and the scanning stage are located inside the variable temperature insert of a helium cryostat. Microwave signals in the distance modulation mode are used for monitoring the tip-sample distance and adjusting the phase of the two output channels. The ability to spatially resolve the metal-insulator transition in a doped silicon sample is demonstrated. The data agree with a semiquantitative finite element simulation. Effects of the thermal energy and electric fields on local charge carriers can be seen in the images taken at different temperatures and dc biases.
我们报告了一台低温扫描微波阻抗显微镜的仪器装置及实验结果。微波探头和扫描台位于氦低温恒温器的可变温度插口中。距离调制模式下的微波信号用于监测针尖 - 样品间距并调整两个输出通道的相位。展示了在掺杂硅样品中对金属 - 绝缘体转变进行空间分辨的能力。数据与半定量有限元模拟结果相符。在不同温度和直流偏置下拍摄的图像中可以看到热能和电场对局部电荷载流子的影响。
