LTPS离子植入技术介绍.ppt

Beam Monitor Dosimeter Neutralizing System Space Charge Neutralization Process Concept Hot Carrier Effect Channel Effect Charging Effect Pressure and Out gassing Cooling Hot carrier Effect Hot carrier effects are more severe in n-channel transistors due to the higher impact ionization rate of electrons vs. holes Hot Carrier Effect Solution LDD (Light Doped Drain) 2. Lower Vds Channel Effect channel effect can results in poor doping profile and depth control,as well as junction depth shift Channel Effect Solution Disorient the beam direction to all crystal axes Implant through an amorphous oxide layer Predamage on the crystal surface Charging Effect Substrate charge Pressure and out gassing poor vacuum can results in charge neutralization as well as overdose and energy contamination Cooling Beam Power = beam I (mA) * beam energy (kV) = the heat from beam transfer to wafer Safety X-ray Gas High Voltage Phosphorus X-Ray Don’t against the cover Distant from Ion source Area High Voltage Avoid Bypass Interlock Use Ground Bar Gas BF3: Process Gas PH3: Process Gas H2: Dilute and Clean Gas Ar: Clean Gas SDS SDS2 Adsorbent Gas Supplied System SDS Gas Source Technology Adsorption Characteristics Safety-Release Rate Test High Pressure v. Safe Delivery Phosphorus Water, H2O2+H2O Aluminum Foil Zipper bag Chemical Solution HNO3 or KOH + H2O +H2O2 Ion Implanter Introduction Diffusion VS Implantation What is Ion Implant For impurity dope control in fabrication of silicon circuit or device Precisely control impurity doping and profile Low Temperature Operation Other Implant Profile and Active Implant Profile Implant and Active 氣體的平均自由動徑 氣體的平均自由動徑(λ)定義為平均一個粒子在碰撞其他粒子前所走的距離。 λ= 2.33 x 10-20 T / Pd02 (cm) (d0：分子直徑) 在室溫時，平均自由徑與壓力間關係 λ= 5 x 10-3 / P (cm) ( p：torr) 以25°C之空氣，在10-3 torr條件下 λ= 5 x 10-3 / 1x10-3 = 5 (cm) System Overview Ion source Extraction Region Analyzing Magnet Region Quadrapole and Beam Focus Scan System Beam Monitor and