planar devices meaning in Chinese
平面设备
Examples
- At the initial stage of planar technique , b was employed as ideal diffusion impurity in base - region of npn si planar devices because of the match of its solid - solubility and diffusion coefficient in si with those of p in emission - region , and the good shield effect of sio2 film to b . but because of the relatively large solubility ( 5 1020 / cm3 at 1000 ) and the small diffusion coefficient , the linear slowly - changed distribution of acceptor b in pn junction can not be formed , which could not cater to the requirement of high - reversal - voltage devics . thereafter b - a1 paste - layer diffusion technology and close - tube ga - diffusion technology had been developed , while the former can lead to relatively large the base - region deviation and abruptly varied region in si , which caused severe decentralization of current amplification parameter , bad thermal stability and high tr ; the latter needed the relatively difficult pack technique , with poor repeatability , high rejection ratio , and poor diffusion quality and productio n efficiency
在平面工艺初期，由于b在硅中的固溶度、扩散系数与n型发射区的磷相匹配， sio _ 2对其又有良好的掩蔽作用，早被选为npn硅平面器件的理想基区扩散源，但b在硅中的固溶度大( 1000时达到5 10 ~ ( 20 ) ，扩散系数小， b在硅中的杂质分布不易形成pn结中杂质的线性缓变分布，导致器件不能满足高反压的要求，随之又出现了硼铝涂层扩散工艺和闭管扩镓工艺，前者会引起较大的基区偏差，杂质在硅内存在突变区域，导致放大系数分散严重，下降时间t _ f值较高，热稳定性差；后者需要难度较大的真空封管技术，工艺重复性差，报废率高，在扩散质量、生产效率诸方面均不能令人满意。