Progress in technology largely depends on the continued miniaturization of electronic components. Smaller components will enable increased switching speeds and device densities for faster computing, larger memory capacity, and improved digital image quality. The current state-of-the-art devices are already below 10nm in size.
Characterizing these devices is becoming increasingly challenging because traditional techniques, such as Secondary Ion Mass Spectrometry (SIMS), do not have the required spatial resolution to address such small structures.
An alternative method to study these devices is Scanning Capacitance Microscopy (SCM), an AFM-based technique. SCM produces maps of the distribution of electrically active carriers in semiconductors with high lateral resolution. During an SCM measurement, a metallized probe is brought in contact with a semiconductor sample to form a metal-insulator-semiconductor (MIS) capacitor, with the insulator often being the natively grown oxide.
An AC bias is applied to the sample, which causes the accumulation and depletion of carriers and the resulting capacitance variations are detected with a GHz resonant capacitance sensor.