Ion implanter

The ion implanter (the medium current ion implanter ULVAC IMX3500, which is able to accelerate ion from 10 KeV to 200 KeV) is a powerful tool which is usually used to modify the electronic properties of the substrate. The concentration profile of the impurity can be precisely controlled with ion current, ion energy and implantation time. In general, the ion implanter can be divided into ion source system, analyzing system, accelerating system, focusing system, target chamber, vacuum system, and control system, as shown in the below figure.

The filament in the source chamber is given a high voltage to produce free electron, colliding with source gas to create plasma. After the chamber pressure increased to mpa range, plasma is generated in the source chamber and ion are extracted by electrodes and selected via mass spectrometry. Finally the ions are accelerated, focused and controlled by multiple electrode and lens to implant into target substrate with scanning spot beam fashion. The system is maintained at a good vacuum condition about 10-6 pa to preserve the purity of the source and prevent the ion scattering in the target system.

Ion