一、引言最近,微波低噪声晶体管有了显著的进展,据称,已有晶体管实际应用于X波段。我们已报告了由于成功地研制了硅npn平面型的微波低噪声晶体管,好的晶体管已达到6千兆赫下,最小噪声系数F_(min)=3.3分贝。此种晶体管要求实现在微细结构中具有必要的杂质浓度。但是,要实现微细的平面图形,有必要进一步改善光刻技术及其相应的掩模对位装置,由于光波长的原因,使这些方法有局限,因此有必要采用电子束曝光技术。此外,对于深度方向的微细图形,即实现浅而且有一定杂质浓度的扩散层的问题,首先,由于扩散基区层的杂质在扩散发射 I. Introduction Recently, microwave low-noise transistors have made significant progress. Allegedly, transistors have been actually used in the X-band. We have reported that due to the successful development of a silicon npn planar microwave low noise transistor, a good transistor has reached 6 GHz with a minimum noise figure F min = 3.3 dB. Such a transistor is required to achieve the necessary impurity concentration in the fine structure. However, to achieve a fine planar pattern, it is necessary to further improve the lithography technique and its corresponding mask alignment apparatus, which have limitations due to the wavelength of light, and therefore it is necessary to use the electron beam exposure technique. In addition, for the fine pattern in the depth direction, that is, the problem of realizing a diffusion layer having a shallow and constant impurity concentration, first, since impurities of the diffusion base layer are diffused and emitted