Very high spatial resolution space charge measurement using electro-acoustic reflectometry (EAR)

Among the materials that find various applications in today's science and industry are insulating or dielectric materials. In electronics and electrical engineering they are used mainly as insulators in components such as capacitors and transistors. Mechanical, thermal, and dielectric properties must be taken into consideration when choosing a dielectric material for a specific use. One of the most important properties of a dielectric material is its breakdown electric field, which is the strongest electric field that can be supported by the material. When a dielectric material is put under electric stress, electric charges can be injected into it from the electrodes, and trapped in the interior. These charges can accumulate over time, generating an internal electrical field, which adds to the applied electric field and may weaken the dielectric strength of the material [1]. This effect is particularly disturbing in the context of biasing transistors, because it gives rise to a bias threshold varying with time.