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o r B I o n I m p l a n t o r Di f f u s i o n O. D o pe d S i O2 P o r B I o n I m p l a n t o r Di f f u s i o n Ion Implant in Process Flow Implant Diffusion Test/Sort Etch Polish Photo Completed wafer Unpatterned wafer Wafer start Thin Films Wafer fabrication (frontend) Hard mask (oxide or nitride) Anneal after implant Photoresist mask . 離子注入原理 . 物理原理 () 通過改變高能離子的能量,控制注入離子在靶材料中的位置。 a) Low dopant concentration (n–, p–) and shallow junction (xj) Mask Mask Silicon substrate xj Low energy Low dose Fast scan speed Beam scan Dopant ions Ion implanter b) High dopant concentration (n+, p+) and deep junction (xj) Beam scan High energy High dose Slow scan speed Mask Mask Silicon substrate xj Ion implanter – 重離子在材料中與靶原子的碰撞是“彈性”庫侖散射 )(( 4 0 ?fEMM MMEtitiT )??– 級聯(lián)散射 Energy Loss of an Implanted Dopant Atom Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si Xrays Electronic collision Atomic collision Displaced Si atom Energetic dopant ion Silicon crystal lattice Figure – 能量損失: 散射路徑 R,靶材料密度 ?,阻止本領(lǐng) S ?????????EenEEtotpenueltotESESdEESdEdxdEdEERdxdEdxdEdxdE000)()()(()(((??)))– 能量損失 – 注入離子的分布 N( x)(無電子散射) 注入劑量 ?0( atom/cm2),射程: Rp 標(biāo)準(zhǔn)偏差 ?Rp Scanning disk with wafers Scanning direction Faraday cup Suppressor aperture Current integrator Sampling slit in disk Ion beam – 對于無定型材料, – 有: 為高斯分布 – 97頁 圖 ??????????????????????2021exp2)(ppp RRxRxN????????????titipp M