SRIM程序介绍.ppt

SRIMASIPPSRIM程序介绍谭模强2005年6月1日SRIMASIPPoutline概括介绍SRIMSRIM的应用SRIMASIPPSRIMASIPPSRIM is a group of programs which calculate the stopping and range of ions into matterMETHOD ：Using a full quantum mechanical treatment of ion-atom collisions.(SRIM always referes to the moving atom as an “ion“, and all target atoms as “atoms“)SRIMASIPPSRIM consists of two main programs, and several special-purpose programs. vSR(Tables of Stopping and Ranges of ions in simple targets). quickly creates Tables of the stopping and range of ions in matter over a wide band of ion energies.vTRIM (the Transport of Ions in Matter) is a Monte-Carlo calculation which follows the ion into the target, making detailed calculations of the energy transferred to every target atom collision. (multi-layer complex targets) SRIMASIPP蒙特卡罗模拟方法(M-C 方法) 通过计算机模拟跟踪一大批 入射粒子的运动。

粒子的位置、能量损失以及次级粒子的各种 参数都在整个跟踪过程中存储下来, 最后得到各种所需物理量 的期望值和相应的统计误差在M-C 方法计算过程中采用连续 慢化假设, 即入射离子与材料靶原子核的碰撞采用两体碰撞描 述, 这一部分主要导致入射离子运动轨迹的曲折, 能量损失来 自于弹性能量损失部分, 而在两次两体碰撞之间认为入射离子 与材料中的电子作用连续均匀地损失能量, 当入射为重离子时 可认为在这期间入射离子作直线运动, 能量损失来自于非弹性 能量损失部分两次两体碰撞之间的距离以及碰撞后的参数通 过随机抽样得到SRIMASIPPMonte-Carlo TRIM is very versatile:vIt will handle ion energies from 10 eV to 2 GeV/amu, and targets with up to eight layers, made up of twelve different elements.vIt will calculate both the final 3D distribution of the ions and also all kinetic phenomena associated with the ion's energy loss: target damage, sputtering, ionization, and phonon production. All target atom cascades in the target are followed in detail.v This program is more accurate in calculating ion ranges than the transport program used in the SR program to produce the range tables described above. SRIMASIPPStopping power:入射粒子在单位路程上损失的能量(-dE/dx).Range:入射粒子从进入靶起到停止点所通过的总的路程,称为射程 . Projected Range: 以Rp表示射程在入射方向投影的长度,称作投影 射程. SRIM相关名词SRIMASIPP左边的示意图是一个能 量E,有入射角的入射粒 子在物质中的轨迹。

是粒子在靶物质中所走过的路程， 是与入射方向平行 的射程， 是与入射方向垂直的射程， 与入射表面垂直 的射程SRIMASIPPIon :入射粒子 Atom :靶原子 Recoil atoms: 与入射粒子发生位移碰撞的反冲靶原子Straggle: 射程是具有统计性质的,不完全一致,而有小的统计变化Cascade:由于一个初级撞出原子而导至众多的原子发生位移的过程Vacancy: 晶格中某个原子被移去后所形成的缺陷Interstitial atoms:填隙原子是指在正常排列的晶格原子位置之间插 入的多余原子.Backscattered Ions:从入射表面进来又从入射表面出去的入射粒子Transmitted Ions:从入射表面进来从背面出去的入射粒子Sputtered atoms:被入射粒子碰撞而离开入射表面的靶原子SRIMASIPPDisplacement Collisions : The process where an energetic incident atom knocks a lattice atom off its site. Replacement Collisions : Atom sites with new atoms, identical to their original atom (this is discussed below). This is the only mechanism in which a vacancy may be re-occupied. Ionization : is energy loss to the target electrons. The electrons of the target absorb energy from the fast moving ions and recoil atoms, and then release it as heat if the target is a metal, or as phonons if the target is an insulator.Phonons : are energy stored in atomic vibrations in a crystal. Since all the atoms in a crystal are linked, when you start vibrating one of them, then all the others start vibrating also. This mass vibration is described as a phonon, since it is somewhat quantized (certain vibration modes are preferred). SRIMASIPPDisplacement Energy( ):发生原子位移所必须的最小能量。

Lattice Binding Energy( ): This is the energy that every recoiling target atoms loses when it leaves its lattice site and recoils in the target. Typically it is about 1 - 3 eV, but values are not known for most compounds. Surface Binding Energy( ) : This is the energy that target atoms must overcome to leave the surface of the target (units = eV). Final Energy(of a moving atom)( ):below which it is considered to be stopped . Final Energy is an energy below any of the above energies .SRIMASIPPAssume: incident atom has atomic number , energy E . collision within the target with an atom of atomic number . After the collision, the incident ion has energy and the struck atom has energy . If > ,then Atomic Displacement ,If > , > then vacancy,If > , < , = then replacement collision ,if , then becomes a stopped interstitial atom. If < , < then becomes an interstitial and + is released as phonons ,SRIMASIPPDisplacements = Vacancies + Replacement CollisionsVacancies = Interstitials + (Atoms which leave the target volume)入射粒子产生级 联碰撞的示意图SRIMASIPP置换碰撞的示意图溅射的示意图SRIMASIPPSRIM的应用SRIMASIPP入射粒子的数据靶对象的数据（元素，原子 质量，入射粒 子能量范围）（元素，状态 ，原子质量， 各成分所占比 例）SRIMASIPP简单的介绍具体的数据可以根据需要求得入射粒子具体的能量对应的停止能量损失 。

SRIMASIPPTRIM具体的输入表格和菜单SRIMASIPP输入部分：入射粒子——NameMassEnergyAngle of Incidemce靶——Layer nameWidthElements 计算损伤类型:Quick:采用 Kinchin-Pease模型来快速计算靶损伤情况8层,12种元素，不关注靶损伤的详细情况或者溅射Full Damage Cascade:该项跟踪每一个反冲核直到它们的能 量低于靶原子的位移阈能. 3层,4种元素SRIMASIPP输出窗口SRIMASIPPTRIM的输出文件TRIM Individual Ion DataTable A 1- RANGE_3D.TXT (Final 3D Ion Di。