SUPRESSION OF SHORT-CHANNEL EFFECT IN MOSFET WITH UV EXCIMER LASER DOPING

采用激光CVD沉积掺杂源和激光熔化引入掺杂剂的两步激光掺杂技术，形成了具有很高表面浓度的浅结。这种技术的特点进行了详细的研究，在薄层电阻和掺杂的档案。通过改变掺杂剂沉积过程中照射的激光脉冲数和硅熔化过程中的激光脉冲数，可以在很宽的范围内精确地控制薄层电阻。可以形成具有很高表面浓度（1 × 10 ~（-3）cm ~ 3）的很浅（0.1 μ m）结<20>，表明该工艺适用于MOSFET源漏区的形成，采用准分子激光两步掺杂，在SOS（蓝宝石上硅）上制造p沟道MOSFET。使用两步掺杂形成源极和漏极层。除了LPCVD栅氧化层在450 ℃下沉积外，器件在室温下加工。制备的高质量MOSFET的开/关比为7，场效应空穴迁移率为145 cm^2/Vs

Two-step laser doping technique consisting of the deposition of dopant source by laser CVD and the introduction of dopant by laser melt was proposed to form very shallow junctions with very high surface concentrations. Characteristics of this technique were investigated in details in terms of sheet resistance and doping profiles. Changing the number of irradiated laser pulse in the dopant deposition process and the number of laser pulse in the silicon melting process, sheet resistance can be controlled precisely in the wide range.Very shallow (0.1mum) junctions with very high surface concentration (1x10^<20>cm^3) can be formed, indicating that this technique is applicable to form the source and drain region of MOSFETs.Using the two-step doping with excimer laser, p-channel MOSFETs were fabricated on SOS (silicon on sapphire) . Source and drain layrs were formed using two-step doping. Devices were processed at room temperature except for the LPCVD gate oxide deposited at 450C.High-quality MOSFETs were fabricated with on/off ratio of 7 and a field effect hole mobility of 145 cm^2/Vs