Haoyu Li, D. Raj, Y. J. Hu
Jun 1, 2017
2017 17th International Workshop on Junction Technology (IWJT)
As transistor technologies continue to scale and device density increases, junction formation requirements are subject to increasing challenges. Ion implantation is the preferred approach for junction formation due to its precise control of dopant depth and dose. These aspects are crucial to deliver finely tuned transistor performance and limit device variation. Arsenic and phosphorus (n-type) dopants are used at many process steps to dope crystalline silicon, polycrystalline silicon, or other substrates in advanced memory devices. Arsenic, due to its heavy mass, will readily amorphize crystalline silicon, particularly at high dose rates. Conventional thermal processing is used to recover crystalline silicon amorphization, but may be subject to residual defects. Heating the substrate during implantation is a novel technique, which has been adopted in advanced semiconductor devices to limit the amorphous region and allow for complete recrystallization in subsequent thermal processes . This work demonstrates wafer-level results of heating the substrate in a plasma doping (PLAD) tool.