MINATEC

Characterisation of state-of-the-art semiconductors has become increasingly difficult as the dimensions of these devices have reached the nano-scale. Some of the most challenging properties of these devices which need to be understood include the locations of the active dopants in the source and drain of the devices and the strain which is used to improve the electron mobility in the conduction channels.

Characterisation of state-of-the-art semiconductors has become increasingly difficult as the dimensions of these devices have reached the nano-scale. Some of the most challenging properties of these devices which need to be understood include the locations of the active dopants in the source and drain of the devices and the strain which is used to improve the electron mobility in the conduction channels. By accurately knowing the electrical properties of these devices, the properties can be optimised which will improve their speed and reduce both their cost and power consumption. Electron holography is a transmission electron microscopy based technique that uses an electron biprism to form an electron interference pattern. From the interference pattern both phase and amplitude images can be reconstructed. As the phase of an electron is dependent on the electro-magnetic and strain fields in the specimen, in principle 2D and 3D maps can be reconstructed revealing the dopant potentials and strain in these devices. This subject will involve the development of electron holography for the development in nanoscience. The candidate will be trained how to use our state of the art FEI Titan TEM to perform electron holography. In particular the candidate will be trained how to use our dual-beam focused ion beam systems to be able to prepare specimens that contain nm-scale semiconductor devices for analysis. This step is critical as specimen preparation can modify the devices, combinations of low-energy milling, plasma etching and laser irradiation can be used to optimise the specimens before examination in the microscope. Within this subject we will develop these techniques to accurately measure the potentials and strain in nm-scale semiconductor devices.