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1.
陈蔚 《数学研究》2002,35(2):109-123
考虑热引导半导体设备中的传输行为,用一个有限元法离散电子位势所满足的Rpoisson方程;用隐式-显式多步有限元法处理电子密度和空洞密度满足的两个对流-扩散方程,热传导方程用隐式多步有限元法离散,推导了优化的L^2范误差估计。  相似文献   

2.
The transient behavior of a semiconductor device is described by a system of three quasilinear partial differential equations. One is elliptic in form for the electric potential and the other two are parabolic in form for the conservation of electron and hole concentrations. The electric potential equation is discretized by a mixed finite element method. The electron and hole density equations are treated by a Galerkin method that applies a variant of the method of characteristics to the transport terms. Optimal order convergence analysis in L2 is given for the proposed method.  相似文献   

3.
The mathematical model of semiconductor devices is described by the initial boundary value problem of a system of three nonlinear partial differential equations. One equation in elliptic form is for the electrostatic potential; two equations of convection-dominated diffusion type are for the electron and hole concentrations. Finite volume element procedure are put forward for the electrostatic potential, while upwind  相似文献   

4.
三维热传导型半导体问题的特征混合元方法和分析   总被引:5,自引:0,他引:5  
本文研究三维热传导型半导体态问题的特征混合元方法及其理论分析,其数学模型是一类非线性偏微分方程的初边值问题,对电子位势方程提出混合元逼近,对电子,空穴浓度方程笔挺表限元逼近;对热传导方程采用对时间向后差分的Galerkin逼近,应用微分方程先验估计理论和技巧得到了最优阶L^2误差估计。  相似文献   

5.
半导体器件瞬态模拟的对称正定混合元方法   总被引:3,自引:3,他引:0  
提出具有对称正定特性的混合元格式求解非稳态半导体器件瞬态模拟问题。提出一个最小二乘混合元方法、一个新的具有分裂和对称正定性质的混合元格式和一个解经典混合元方程的对称正定失窃工格式求解电场位势和电场强度方程;提出一个最小二乘混合元格式求解关于电子与空穴浓度的非稳态对流扩散方程,浓度函数和流函数被同时求解;采用标准的有限元方法求解热传导方程。建立了误差分析理论。  相似文献   

6.
半导体瞬态问题的数学模型是由四个方程组成的非线性偏微分方程组的初边值问题所决定.其中电子浓度和空穴浓度方程往往是对流占优扩散问题,普通的方法已不适用,为此本文用迎风格式处理对流项部分,提出一种全离散迎风有限体积元方法,并进行收敛性分析,在最一般的情况下得到了一阶精度L2模误差估计结果.  相似文献   

7.
提出交替方向特征有限元方法,对电场位势方程采用混合元格式,对电子,空穴浓度方程采用交替方向特征有限元格式,对温度方程提出交替方向格式.应用向量积计算及先验估计理论和技巧,得到最佳的L2误差估计.  相似文献   

8.
热传导型半导体瞬态问题的数学模型是一类非线性偏微分方程的初边值问题.电子位势方程是椭圆型的,电子、空穴浓度方程及热传导方程是抛物型的.该文给出求解的配置方法,得到次优犔2模误差估计,并将配置法和Galerkin有限元方法进行数值结果比较.  相似文献   

9.
半导体器件的瞬时状态由包含3个拟线性偏微分方程所组成的方程组的初边值问题来描述.在三角剖分的基础上,对椭圆型的电子位势方程采用混合有限体积元法来逼近,对对流扩散型的电子浓度和空穴浓度方程采用迎风有限体积元方法来逼近,并进行了详细的理论分析,得到了最优阶的误差估计结果.最后,针对混合有限体积元法和迎风有限体积元法分别单独使用以及两种方法结合使用的情形给出了不同的数值算例.  相似文献   

10.
半导体器件瞬时状态的模型由三个非线性偏微分方程组所决定.一个是关于电子位势的方程外型是椭圆的,另两个是关于电子和空穴浓度方程外型是抛物的,电子位势通过其电场强度在浓度方程中出现,以及相应的边界和初始条件.我们讨论平面区域Ω上的问题:  相似文献   

11.
本文研究三维热传导型半导体瞬态问题的特征有限元方法及其理论分析,其数学模型是一类非线性偏微分方程的初边值问题,对电子位势方程提出Galerkin逼近;对电子,空穴浓度方程采用特征有限元逼近;对热传导方程采用对时间向后差分的Galerkin逼近.应用微分方程先验估计理论和技巧得到了最优阶L^2误差估计。  相似文献   

12.
For the transient behavior of a semiconductor device, the modified method of characteristics with mixed finite element domain decomposition procedures applicable to parallel arithmetic is put forward. The electric potential equation is described by the mixed finite element method, and the electric, hole concentration and heat conduction equations are treated by the modified method of characteristics finite element domain decomposition methods. Some techniques, such as calculus of variations, domain decomposition, characteristic method, energy method, negative norm estimate and prior estimates and techniques are employed. Optimal order estimates in L2 norm are derived for the error in the approximation solution. Thus the well‐known theoretical problem has been thoroughly and completely solved.© 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 353–368 2012  相似文献   

13.
Transient behavior of semiconductor with heat-conduction on nonrectangular is studied using isoparametric elements and an approximation to the Jacobian of the isoparametric map.Concentration and heat-conduction equations are solved by alternating-direction methods and electric potential equation is approximated by finite element method.Optimal order error estimates in L^2 are demonstrated using the theory and technique of a prior estimate of differential equation.  相似文献   

14.
Characteristic finite difference fractional step schemes are put forward. The electric potential equation is described by a seven-point finite difference scheme, and the electron and hole concentration equations are treated by a kind of characteristic finite difference fractional step methods. The temperature equation is described by a fractional step method. Thick and thin grids are made use of to form a complete set. Piecewise threefold quadratic interpolation, symmetrical extension, calculus of variations, commutativity of operator product, decomposition of high order difference operators and prior estimates are also made use of. Optimal order estimates in l2 norm are derived to determine the error of the approximate solution. The well-known problem is thorongley and completely solred.  相似文献   

15.
赵卫东 《计算数学》2000,22(1):83-96
1.引言多孔介质二相驱动问题的数学模型是偶合的非线性偏微分方程组的初边值问题.该问题可转化为压力方程和浓度方程[1-4].浓度方程一般是对流占优的对流扩散方程,它的对流速度依赖于比浓度方程的扩散系数大得多的Farcy速度.因此Darcy速度的求解精度直接影响着浓度的求解精度.为了提高速度的求解精度,70年代P.A.Raviat和J.M.Thomas提出混合有限元方法[5].J.DouglasJr,T.F.Russell,R.E.Ewing,M.F.Wheeler[1]-[4],[9],[12]袁…  相似文献   

16.
刘伟  袁益让 《计算数学》2006,28(2):175-188
半导体器件的瞬时状态由三个方程组成的非线性偏微分方程组的初边值问题决定,电子位势方程是椭圆型的,电子和空穴浓度方程是抛物型的.依据实际数值模拟的需要,提出了一类三维半导体问题在时间和空间上进行局部加密的复合网格上的有限差分形式,并给出了电子和空穴浓度的最大模误差估计,最后给出了数值算例.  相似文献   

17.
构造具有广义边界条件的四阶线性抛物型方程的混合间断时空有限元格式,利用混合有限元方法将高阶方程降阶,利用空间连续而时间允许间断的时空有限元方法离散方程,证明了离散解的存在唯一性,稳定性和收敛性,并给出数值算例验证了方法的有效性.  相似文献   

18.
Transient behavior of three-dimensional semiconductor device with heat conduction is described by a coupled mathematical system of four quasi-linear partial differential equations with initial-boundary value conditions. The electric potential is defined by an elliptic equation and it appears in the following three equations via the electric field intensity. The electron concentration and the hole concentration are determined by convection-dominated diffusion equations and the temperature is interpreted by a heat conduction equation. A mixed finite volume element approximation, keeping physical conservation law, is used to get numerical values of the electric potential and the accuracy is improved one order. Two concentrations and the heat conduction are computed by a fractional step method combined with second-order upwind differences. This method can overcome numerical oscillation, dispersion and decreases computational complexity. Then a three-dimensional problem is solved by computing three successive one-dimensional problems where the method of speedup is used and the computational work is greatly shortened. An optimal second-order error estimate in L2 norm is derived by using prior estimate theory and other special techniques of partial differential equations. This type of mass-conservative parallel method is important and is most valuable in numerical analysis and application of semiconductor device.  相似文献   

19.
1 引 言设Ω R2为具有光滑边界的有界区域,考虑非定常的,无量纲化的,而且带有热传导的粘性不可压缩流体力学问题:问题(Ⅰ):求u=(u1,u2),p,T满足:  相似文献   

20.
刘蕴贤 《计算数学》2001,23(2):187-198
1.引言 三维热传导型半导体器件瞬态问题的数学模型由四个非线性偏微分方程描述 [1,2].工程研究中一般考虑绝流边条件,由于绝流条件可以看作一反射条件来处理、为了数值分析方便,我们在此考虑三维周期问题: 其中, =[0,1]3,未知函数是电子位势 ;电子,空穴浓度e,p;温度函数T.方程(1,1)-(1.4)中出现的系数均有正的上下界,且是 周期的. a=Q/ε,Q,ε分别表示电子负荷和介电系数,均为正常数.N(x)是给定的函数.Ds(x)为扩散系数,μs(x)为迁移率,s=e,P.R(e,p,T)…  相似文献   

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