Tomography of Electrical Data in Advanced-Node SRAMs

A commercially available 6T SRAM was examined with an AFM-in-SEM system. A conductive AFM measurement was taken using an AC bias on the backside of the sample with a linear amplifier on the data. Then using a cone-shaped, diamond AFM tip, subsequent scans were made over the field of view at increasingly higher downforce until areas of the chip were worn away. The results provide a survey of implants and structure milling from contact level through the wells of the device. An additional experiment was performed with EBAC.