LPCVD制备二氧化硅薄膜工艺研究

采用TEOS源LPCVD法制备了SiO2薄膜,采用膜厚仪对薄膜的厚度进行测试.通过不同条件下SiO2薄膜的厚度变化,讨论了TEOS源温度、反应压力及反应温度等工艺条件对淀积速率和均匀性的影响.结果表明,在40℃,50 Pa左右,淀积速率随TEOS源温度、反应压力基本呈线性增大.通过多次试验改进,提出了SiO2膜淀积的典...     

变温LPCVD沉积氮化硅薄膜的均匀性优化

以低压化学气相沉积(LPCVD)热壁立式炉为实验平台,由二氯硅烷和氨通过LPCVD工艺合成氮化硅薄膜,利用降温成膜提高氮化硅薄膜的膜厚均匀度.基于气体碰撞理论建立了氮化硅薄膜沉积速率与反应气体浓度的关系式.分析比较了LPCVD炉内不同升温速率沉积氮化硅薄膜的表面性能.发现在变温沉积阶段,选择合适的降温速率是实现薄膜沉积...     

低压沉积温度对MoSi2涂层微观结构与性能影响

以SiCl₄和H₂为原料,采用低压化学气相沉积（LPCVD）渗硅法在Mo基体表面原位反应制备了MoSi₂涂层,研究了沉积温度对MoSi₂涂层微观形貌、物相组成、沉积速率、涂层的硬度、涂层与基体结合强度的影响. 研究结果表明：在1100~1200℃下制备的涂层结构致密,由单一MoSi₂组成,沉积速率、涂层的硬度以及与基体的结合强度均表现为増加的趋势;当沉积温度高于1200℃,涂层出现开裂现象,由游离Si和MoSi₂两相组成,涂层沉积速率、硬度和结合强度均出现下降的趋势. 1100℃以下沉积的主要控制步骤为Si与Mo反应,而1100℃以上Si在涂层中的扩散对沉积过程起控制作用.     

炉管制程工艺中的片数效应及其优化方案

随着半导体技术的发展,越来越多的立式炉管在200mm及300mm集成电路晶圆制造中被应用到。同时炉管制程中的片数效应随着集成电路芯片的集成度越来越高而被凸显出来。文章将以LPCVD氮化硅在0.16μm、64M堆叠式内存制造过程中的片数效应为例,阐述炉管制程工艺中的片数效应以及通过调整制程参数（温度、沉积时间）的方式予以解决的实例。文中通过调整炉管上中下的温度来补偿气体的分布不均匀,调整沉积时间来补偿不同片数的沉积速率的差异,两者结合并辅以基于片数的分片程式来解氮化硅电介质沉积的片数效应。同时以此为基础总结出炉管片数效应的解决方案。     

Structural and electrical properties of polycrystalline silicon films deposited by low pressure chemical vapor deposition with and without plasma enhancement

Silicon thin films prepared by chemical vapor deposition of silane at very low pressures (4 mTorr) in an experimental reactor that allows deposition with and without plasma enhancement have been characterized. The temperature range of the substrates on which the films were deposited was varied from 500 to 800° C for plasma-enhanced depositions and 600 to 800° C for nonplasma depositions. Conductivity measurements as a function of temperature as well as average grain size and crystallographic texture measurements were performed. The results indicate that the films deposited with the assistance of a plasma were amorphous at deposition temperatures of 650° C and below and polycrystalline at deposition temperatures of 700° C and above. In the temperature regime investigated, this amorphous-to-crystalline transition was not observed in films deposited without the assistance of a plasma. Furthermore, all the films deposited at temperatures of 650° C and below have been found to have significantly different properties from the similarly prepared films deposited at higher temperatures.     

用多晶硅吸杂和SiO2背封工艺提高硅片质量

我们对多晶硅吸荣和SiO_2背封二种工艺进行了系统的深入的实用性研究，解决了VLSI用外延片衬底的关键技术，提高了硅片质量并实现产业化。多晶硅每炉可生长约100mm（4英寸）硅片150～300片，SiO~2每炉生长100片。由于硅片质量好，工艺稳定，硅片已远销国外。     

半绝缘多晶硅薄膜的钝化与性能研究

通过LPCVD的方法,在Si基体表面制备了掺氧半绝缘多晶硅薄膜(SIPOS),分析了钝化机理,讨论了不同流量比与沉积速率、含氧量的关系以及SIPOS膜的含氧量对膜系结构、电阻率、折射率的性能影响,获得了最佳钝化条件,测试结果表明SIPOS薄膜晶体管击穿电压高、可靠性好、性能更稳定,可以满足现代生产的需要.     

Progress in 4H-SiC homoepitaxial growth by hot-wall LPCVD

Recent progress in 4H-SiC homoepitaxial growth by using hot-wall low-pressure chemical vapor deposition (HW-LPCVD) at the authors' group was reviewed. Horizontal air-cooled low-pressure hot-wall CVD (LPHWCVD) system was developed and employed to get high quality 4H-SiC epilayers. Homoepitaxial growth of 4HSiC on off-oriented Si-face (0001) substrates was performed at a typical temperature of 1 500 ℃ by using the stepcontrolled epitaxy. The typical growth rate was controlled to be about 1.0 μm/h. The background doping was reduced to 2 × 1015- 5 × 1015 cm-3. The FWHM of the rocking curve was 0 308 nm in 2 μm× 2 μm scale. Intentional N-doped and B-doped 4H-SiC epilayers were obtained by in-situ doping of NH3 and B2 H6, respectively. Thermal oxidization of 4H-SiC homoepitaxial layers was conducted in a dry O2 and H2 atmosphere at 1 150 ℃ and 4H-SiC MOS structures was obtained. Schottky barrier diodes with reverse blocking voltage of over 1000 V were achieved preliminarily.     

微桥法研究低应力氮化硅力学特性及误差分析

用微机械悬桥法研究低应力氮化硅薄膜的力学性能。对符合弹性验则的微桥进行测试 ,在考虑衬底变形的基础上 ,利用最小二乘法对其载荷—挠度曲线进行拟合 ,得到低应力lowpressurechemicalvapourdeposited (LPCVD)氮化硅的弹性模量为 3 14 .0GPa± 2 9.2GPa ,残余应力为 2 65 .0MPa± 3 4.1MPa。探讨梯形横截面对弯曲强度计算和破坏发生位置的影响 ,得到低应力氮化硅的弯曲强度为 6.9GPa± 1.1GPa。对微桥法测量误差的分析表明 ,衬底变形、微桥长度和厚度的测量精度对最终力学特性的拟合结果影响最大     

SIPOS薄膜工艺及其稳定性研究

SIPOS半绝缘多晶硅薄膜在分立式器件特别是一些高压器件的钝化中有着广泛的应用,其不仅能够提升器件的反向击穿电压,而且也极大地提高了器件的可靠性。文章阐述了SIPOS薄膜的器件钝化机理,工艺过程中各参数对薄膜特性及应用的影响。同时通过实验设计DOE对LPCVD（化学气相沉积）系统的各个参数进行工程实验,分析了相关参数对薄膜沉积速率及特性的影响,并通过对实验结果的模型推导,得出相关工艺参数与产品电学性能之间的关系实验模型,并进一步阐述了工艺稳定性控制的方法,为SIPOS薄膜在工艺的实际工程应用中以及工艺的稳定性控制上提供可靠的技术支持。