UHV/CVD生长亚微米薄硅外延层及其高频器件研制

Sub-micron silicon epilayer deposited by a novel Ultrahigh Vacuum Chemical Deposition System and fabrication of high frequency device

为获得亚微米级的薄硅外延层,从而提高硅器件的工作频率,利用自行研制的一台新型超高真空化学气相沉积(UHV/CVD)系统生长用于高频器件的超薄外延层,该系统由气路部分、控制部分、主体部分组成,反应室本底真空可达5.0×10-8Pa,能够实现在超净环境下低温、低压外延生长.利用该系统在重掺硅衬底上成功生长出了高质量的亚微米薄硅单晶层,外延层厚度为0.1～0.5μm,掺杂浓度为1×1017cm3,过渡区非常窄,达到了制备高频器件的要求;并在此基础上制备出了高频肖特基二极管原型器件,由IV测试并经过计算,截止频率可达31GHz.

To obtain ultrathin epilayers which are used to improve high frequency characteristic of silicon based devices, a new approach to grow sub-micron silicon epilayer is developed by a novel ultrahigh vacuum chemical vapor deposition system consisting of three chambers and a computer-controlled gas distribution. The base pressure of the reaction chamber could reach 5.0×10-8 Pa. With this system, the sub-micron silicon epilayer is successfully deposited at 600°C. The thickness and carrier concentration of the epilayer is about 0.1-0.5 μm and 1×1017 cm3, respectively. Using the above sub-micron silicon epilayer, a prototype Schottdy Barrier diode is fabricated, whose calculated cutoff frequency could reach 31 GHz.