Explanation

A semiconductor doping process. The dopant atoms are ionized into positive ions by the ion source, and then extracted from the ion source and accelerated to the required energy (typical energy range is 5-200keV). Through the mass analyzer, focusing and mutually perpendicular scanning system, impurity ion implantation are implanted into the semiconductor. After ion implantation, appropriate annealing process is required to activate implanted impurities and eliminate implanted damage. The main advantages of ion implantation are: ① it can accurately control the concentration of injected impurities in a large range, and has good doping uniformity; ② The doping depth can be precisely controlled, increasing the flexibility of device design; ③ It is a low-temperature process, and different photolithographic masks including photoresist are allowed to be used; ④ Impurities can be injected through thin films (such as oxide and nitride films), which can adjust the threshold voltage of MOS transistors after growing the gate dielectric layer; ⑤ It is a non-equilibrium doping process. Impurities that cannot be doped under equilibrium conditions can be doped by ion implantation, and there is no limit on solid solubility. ion implantation is almost the only means of doping in integrated circuit manufacturing. Except in the field of semiconductor manufacturing. ion implantation can also be used in other fields, such as surface modification of metallic materials.

Classification