The behavior of oxygen precipitation in heavily doped silicon was investigated. The experimental results showed that the behavior of oxygen precipitation in heavily doped silicon is not only related to initial oxygen concentration, but also is affected by dopant species. The growth of oxygen precipitation was not affected by dopant type. Dopant species only influenced the nucleation of oxygen precipitation, and the time of precipitate nucleus formation is shorter in P+ samples than in N+ samples. The morphology of oxygen precipitation is independent of dopant type and only depends on the heat-treatment cycles. Considering the hanging bond on the interface of Si-SiO at precipitates embryo and amending the free energy item, an expression of nucleation critical radius associated with dopant species was derived, and the dependent relationship of oxygen precipitation behavior in heavily doped silicon and dopant species was explained by this model. Moreover, an effective intrinsic gettering cycle with suitable width of denuded zone in heavily Sb-doped silicon samples was obtained in order to reduce or eliminate the metallic impurities and unwanted defects in the surface of substrate and device active regions.

Flow pattern defects (FPDs) is one kind of grown-in defects in large diameter Czochralski silicon (Cz-Si) crystals. The evolution of FPDs in lightly doped Cz-Si crystals during secco etchant (50% HF: 0.15 mol L-1 K2Cr2O7=2:1) etching process, was studied in detail firstly. The results also showed that the outline of FPDs became larger and the voidon the tip of FPDs changed into a shallow hole with the increasing of etching time. A parabola model was firstly put forward to explain the evolution of FPDs in Cz-Si wafers during the procedure. Furthermore, the microstructure of FPDs was observed by optical microscopy andatomic force microscopy, the results showed that the outline of FPDs was parabola with several steps and two heaves were firstly foundon the left and right sides of the voidon the tip of FPDs. All the results provide forceful evidence to that FPDs is one kind of void-type as-grown defects. These are very useful to investigate FPDs in Cz-Si wafers further and explain the annihilation of FPDs during high temperature annealing processes.

In this paper, the theory analysis and experiments on the semiconductor silicon crystal growth under the equivalent micro-gravity, which induced by a permanent magnetic field, were investigated. The experimental results show that the crystal growth in the equivalent micro-gravity is similar to that in the space. The homogeneity of doping and the oxygen concentration in CZSi by using the permanent magnetic field, can be improved, because of restriction of the convection, compared with the crystal growth in the conventional CZ method. Diffusion kinetics are dominated during movement of mass in melt under the equivalent micro-gravity, different from that in the conventional CZ method.

The characteristics and annealing behavior of vacancy clusters in neutron transmutation doped silicon (NTDSi) were investigated by means of Fourier transform infrared spectroscopy (FTIR) and photoinduced transient spectroscopy. FTIR results showed that three IR absorption peaks at 707, 742, and 776 cm-1 occurred during annealing NTDSi samples at temperatures ranging from 350 to 600℃. By comparing the present results with those reported earlier, the defect center (we named it the P0 center) which gives rise to these IR absorption bands, was assumed to be a multivacancy cluster consisting of at least six vacancies. Photoinduced transient spectroscopy results showed that a P0 center introduced two acceptor levels at EC-0.427 eV and EC-0.524 eV inside the energy gap.

In this investigation, Czochralski grown silicon (CZ-Si) was irradiated by a fast neutron which can introduce irradiated defects into silicon and change the quality and density of point defects in silicon, by the interaction between irradiated defects and oxygen, the controlled precipitation of oxygen, and an excellent intrinsic gettering structure in CZ-Si during heat treatment cycles can be obtained easily.

Growth of Czochralski (CZ) silicon crystals under the magnetic field induced by a cusp-shaped permanent magnet of NdFeB has been investigated. It is found that the mass transport in silicon melt was controlled by its diffusion while the magnetic intensity at the edge of a crucible was over 0.15 T. In comparison with the growth of conventional CZ silicon without magnetic field, the resistivity homogeneity of the CZ silicon under the magnetic field was improved. Furthermore, the Marangoni convection which has a significant influence on the control of oxygen concentration was observed on the surface of silicon melt. It is suggested that the crystal growth mechanism in magnetic field was similar to that in micro-gravity if a critical value was reached, named the growth of equivalent micro-gravity. The relationship of the equivalent micro-gravity and the magnetic intensity was derived as g=(v0/veff)g0. Finally, the orders of the equivalent micro-gravity corresponding to two crucibles with characteristic sizes were calculated.

The flow pattern defects (FPDs) in as-grown and rapid thermal annealed <100> boron-doped CZSi wafers were investigated in this paper. The experimental results showed that a hole occurred on the apex of FPDs observed by atomic force microscope. The changes in the number and the size of the FPDs in as-grown and annealed wafers were measured by optical microscope after etching in Secco etchant. The size of FPDs became smaller, the density of FPDs reduced above 1100℃ annealing and became very low above 1200℃ annealing in an Ar atmosphere; the hole on the apex became shallower and larger. This mechanism was discussed.

对大直径重掺锑硅单晶中流动图形缺陷（FPDs）进行了研究.利用高温快速退火工艺（RTA），将重掺锑硅片在N2，Ar，H2三种不同气氛下进行热处理，对退火前后FPDs 的密度变化进行了研究，分析了重掺锑硅单晶中FPDs在不同高温RTA过程中的热稳定性.并从重掺杂原子锑与间隙氧之间的关系，分析了重掺锑硅片中FPDs在高温快速退火工艺下的消除机制，认为重掺锑硅单晶中大量的锑原子，影响了硅片中间隙氧的浓度分布，进而影响了原生微缺陷的形成及热行为。