利用装置环形永磁场的直拉炉(PMCZ)生长单晶硅和掺锗硅晶体
Monocrystalline Silicon and Ge-Doped Si Growth with Ring Permanent Magnetic Field
摘要 设计了一种永磁(钕铁硼)环形磁场装置代替常规电磁场用于直拉炉生长单晶硅和掺锗单晶硅(PMCZ法).磁力线呈水平辐射状均匀分布.只要磁场强度足够强,即可有效地抑制熔体中热对流和晶体旋转产生的离心强迫对流,从而有效地抑制了固液界面处的温度波动,降低以至消除微观生长速率的起伏,造成了一种类似于空间微重力环境下生长晶体的条件.在这种条件下,杂质和掺杂剂的运动方式受扩散规律控制.利用这种装置生长了掺锗(Ge∶Si重量比为1.0%,5.0%和10.0%)和不掺锗的硅晶体,获得了氧浓度较低,掺杂剂径向分布均匀性好的较高质量的晶体.该装置磁场强度可方便地通过调节磁环之间相对位置及磁环相对固液界面位置进行调控,满足不同工艺条件对不同的场强的要求.
Abstract:
A permanent magnetic field has been fabricated to replace the conventional electrical magnetic field,which is applied in a novel magnetic device for CZSi growth called PMCZ.Czochralski silicon(CZSi)and Ge-doped Si are grown in ring permanent magnetic fields.With magnetic line of force being a horizontal radialized distribution.Thermal convection in the melt and the centrifugal pumping flows due to the crystal rotation can be suppressed by the ring permanent field,effectively so can the temperature fluctuations and the microscopic growth-rate fluctuations at the solid-liquid interface.In magnetic fields,crystal growth is similar to that in the space of weightless impurity motion is diffusion-controlled.Crystal with lower oxygen concentration and the more homogeneous dopant in the radial direction was grown in such conditions.In this paper,Ge-doped concentration is 1.0%,5.0% and 10.0% respectively(Ge∶Si,weight ratio).The magnetic intensity can be adjusted by changing the location of the interface between magnetic device and melt-crystal or the positions between 2 or 3 magnetic rings,thus it can meet the needs of crystal growth comparing the electrical magnetic field and the permanent one,we find the later does not consume any electricity or water,but has more steady,magnetic field intensity,so that the crystal’s production cost can be reduced.
Author: ZHANG Wei-lian SUN Jun-sheng ZHANG En-huai LI Jia-xi
作者单位: 河北工业大学材料研究中心,
刊 名 半导体学报 ISTICEIPKU
年,卷(期): 2001, 22(3)
分类号: TN304.053
机标分类号: TN3 TQ0
在线出版日期: 2004年1月8日
基金项目: 国家自然科学基金