FEMAG晶体生长计算软件FEMAG-CZ - Czochralski Crystal Growth Simulation by FEMAGSoft
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晶体生长仿真软件FEMAG介绍文档(二)主要功能&技术优势FEMAG软件致力于多物理场数值模拟分析晶体材料的生长过程,为用户提供晶体生长输运过程中的重要信息以及影响晶体质量的工艺信息,提高晶体质量与用户的研发效率。
目前,FEMAG软件产品有:FEMAG/CZ、FEMAG CZ/OX、FEMAG/FZ、FEMAG/DS、FEMAG/VB以及FEMAG/PVT,可有效分析提拉法生长、泡生法生长、区熔法生长、定向凝固、坩埚下降法生长、物理气相传输法生长等工艺过程。
FEMAG软件主要具有以下功能:(1)在设计工程领域,利用FEMAG软件可以设计生长熔炉系统中保温套和反射体的形状、材质和位置,可确定加热器的位置,设计辅助加热器,选择与设计保温层。
(2)在质量控制工程领域,利用FEMAG软件可以分析热应力、控制氧/碳含量分布、掺杂物分布以及缺陷的预测,优化工艺参数,提高晶体生长质量。
(3)在成本控制工程领域,利用FEMAG软件可以评估能耗、气耗,也可以评估原料辅料的成本与使用寿命。
FEMAG软件产品及其典型的应用如下图所示:FEMAG软件产品及其典型应用FEMAG软件的主要技术优势➢求解技术先进、高效,求解精度高晶体生长过程是一个高度非线性的、多尺度的复杂问题,涉及导热、对流、辐射与相变,空间尺度与时间尺度跨度范围大。
例如,熔体与气相的传热、传质,湍流,热辐射相互耦合作用,会显著影响晶体的缺陷形成;熔体与气相中存在扩散、粘性、辐射、热边界层,甚至伴有复杂的缺陷边界层,空间尺度跨度大;晶体生长的时间尺度一般慢于热传导时间尺度两个数量级,慢于对流传热时间尺度六个数量级,时间尺度跨度很大等等。
FEMAG软件通过建立考虑多种耦合效应的传热、湍流等全局有限元模型(包括准稳态模型、与时间相关的逆向动态、直接动态模型),基于非结构化网格而开发的Navier-Stokes求解器,结合Newton-Raphson迭代法,可以准确、快速地求解上述多场、多尺度的复杂问题。
晶体⽣长建模软件FEMAG介绍(⼋)--FEMAGPVT(物理
⽓相传输法)
FEMAG/PVT软件的主要功能
FEMAG/PVT软件⽤于模拟物理⽓相传输法(Physical Vapor Transport process,PVT)晶体⽣长⼯艺,可以⽤于碳化硅单晶体、氮化铝、氧化锌多晶体等的PVT法⽣长⼯艺过程的模拟。
FEMAG/PVT软件的典型应⽤
FEMAG/PVT软件的典型应⽤是模拟碳化硅单晶的PVT法⽣长过程。
图1是碳化硅晶⽚。
碳化硅(SiC)是⼀种优质的宽带隙半导体材料,具有宽禁带、⾼击穿电场、⾼热导率、⾼饱和电⼦漂移速率等优点,可以满⾜⾼温、⼤功率、低损耗⼤直径器件的需求。
SiC单晶⽆法经过熔融法形成,⽽基于改进型Lely法的升华⽣长技术——物理⽓相传输法是获得SiC单晶的常⽤⽅法。
PVT法制备SiC单晶的⽣长原理是:⾼纯SiC粉源在⾼温下分解形成⽓态物质(主要为Si、SiC2、Si2C),这些⽓态物质在过饱和度的驱动下,升华⾄冷端的籽晶处进⾏⽣长。
过饱和度是由籽晶与粉源之间的温度梯度引起的。
图2是利⽤FEMAG/PVT软件计算碳化硅沉积腔内的温度梯度的结果。
晶体生长模拟软件FEMAG-CZ Czochralski (CZ) Process(FEMAG-CZ)FEMAG直拉法模拟软件(FEMAG-CZ)用于模拟直拉法工艺(包括Cz, MCz, VCz,泡生法)。
FEMAG-CZ直拉法模拟软件用于新的热场设计,并研发新的方法以满足新的商业需求点,比如:✓大直径晶锭生长✓无缺陷硅晶锭生长✓提高成品率✓氧含量控制✓降低碳含量✓晶锭半径和沿轴向的电阻率差异减小✓CCZ工艺仿真✓磁场设计✓蓝宝石生长工艺设计FEMAG-CZ模拟软件通过降低试验成本而节省了R&D消耗。
大直径晶锭生长以期不进行大量昂贵的可行性试验生长大尺寸晶体看起来是不太现实的。
FEMAG-CZ软件提供这种可能性。
为了生产450 mm及以上的大尺寸无缺陷硅晶体,晶体生长工程师通过使用FEMAG-CZ来定义关键的工艺参数,而无需任何材料和能源的消耗。
FEMAG-CZ能够设计新的热场并研发新的工艺技术,在FEMAG直拉法模拟软件的帮助下,晶体生长工程师能够在一个有效的虚拟环境中优化每一个关键参数,比如旋转速率,提拉速度,气体流速,压强和功率消耗等。
FEMAG直拉法模拟还能进一步为晶体生长工程师给出在某一工艺配置下产出的最终成品的质量和成本信息,比如晶体中的温度梯度,氧/碳/掺杂物/微缺陷分布等。
通过软件能够获得硅/锗/蓝宝石晶体质量和产品成本信息,这一模拟过程无需任何材料和能量的消耗。
FEMAG 3D 熔体流动模拟结果FEMAG动态模拟无缺陷硅晶锭生长无缺陷晶体硅生长是世界上最大的难点之一。
FEMAG模拟软件能够帮助工程师运用自己创新的技术生长出无缺陷晶体。
运用FEMAG软件缺陷工程模块可以预测晶体炉或者其他指定直拉法工艺环境中生长的晶体成品质量。
缺陷工程模块能够洞悉硅、锗生长过程中填隙原子,空位和微孔演变过程。
FEMAG-CZ能够成为你的测试平台,试验在不同的操作条件下对晶体生长质量的影响,如✓热场设计✓加热器功率✓晶体和坩埚的旋转速率✓晶体提拉速度,坩埚的位置✓气体流率和压强一旦掌握了晶体生长工艺中的动态规律,就可以找到最优的配置以增加成品率和投资回报。
FEMAG晶体生长计算软件
FEMAG-CZ - Czochralski Crystal Growth Simulation
by FEMAGSoft
FEMAG-CZ is a global crystal growth simulation software taking into account the furnace geometry, the materials and the operating conditions in order to provide the user with all the information required for his process development and optimization.
Global heat transfer, Thermo-elastic stresses, Defect prediction, Melt flow and Heater power.
Features
∙» Evolution of the solid/liquid interface shape (dynamic simulation)
∙» Thermal gradients in the liquid and solid phase
∙» Heat fluxes in the overall furnace
∙» Thermal-stresses in the crystal and hotzone components
∙» Continuous feeding
∙» Species (dopants and impurities) segregation and concentration
∙» Magnetic fields
Supported Languages:English
Supported Technologies
Operating Systems:Linux
Programming Languages:C/C++
Product Type(s):Software
Additional Product Information
FEMAG family products provide so-called ''global calculations'' , meaning that all the constituents of the furnace are taken into account, together with all heat transfer modes within and between them (conduction, convection and radiation). The modelling of conduction includes the possibility of temperature-dependent and anisotropic conductivity. The modelling of radiative heat exchanges assumes diffuse radiation and can take into account semi-transparent materials through wavelength-dependent radiative properties.
The flow in the melt phase can be modelized by a laminar and/or turbulent model. It takes into account natural convection, due to temperature-dependent density and surface tension, and forced convection due to crystal, crucible and/or polycrystal - in case of the FZ process - rotations, possibly under the influence of a magnetic field (axial, cusp, rotating or transverse). Melt flow calculation also considers the effect of gas flow and of tangential forces due to induction (if any) on melt surface.
The flow in the gas phase, as a result of an imposed flow rate at gas inlet and of temperature-dependent density, can be modelized by a laminar or a turbulent model.
The heating of the process is modelized: ohmic heaters (one or several, coupled or independent) or inductors. In the case of multiple heaters, the user has the possibility to control the heating powers by imposing a specific temperature at given control points.
The shapes of interfaces and free-surfaces of the system are calculated. The solidification front and melting front - in case of the FZ process - shapes are calculated taking into account heat dissipation (or absorption) proportional to the growth rate. The melt/gas interface is calculated, as a result of a balance of surface tension, gravity and normal forces due to induction (for the FZ process), providing an accurate meniscus shape.
The processes can be modelized by a quasi-steady or by a time-dependent model. The quasi-steady model takes into account the effect of growth rate on heat transfer while assuming a fixed position for all constituents. The time-dependent model considers a geometry that evolves due to crystal lengthening and melt shrinking. It also takes into account the transient effects due to the thermal inertia of all constituents, and due to the inertia of the solidification front shape.
Global heat transfer. Temperature isolines are separated by 50 K.。