沟槽式肖特基用高均匀性硅外延支撑层高速生长工艺研究

High-speed growth of epitaxial and uniform silicon support layer for trench Schottky

作为沟槽式肖特基芯片的关键支撑层,硅外延层的性质对芯片性能构成重要影响。系统探索了新式高速外延生长工艺制备硅外延层的方法。通过干涉显微镜、FT-IR、Hg-CV对硅外延层性质进行表征。研究了高速外延生长条件下的厚度均匀性、电阻率均匀性、表面完整性与外延反应流场、热场的作用规律。研究结果表明,通过基座高度的调制、加热功率的分配、预先基座包硅、本征覆盖层生长等综合手段解决了外延层边缘参数控制问题,并实现了最高6.6μm/min的生长速率。

As the main support of trench-type Schottky chip,the silicon epitaxial layer can significantly affect the devices.Here we systematically studied the method to prepare high-uniform silicon epitaxial layer using novel high rate growth method.The properties of the silicon epitaxial layer were characterized by microscopes,FT-IR,Hg-CV and SRP.This work studied the effects of thickness uniformity,resistivity uniformity,surface integrity and corresponding epitaxial reaction flow field and thermal field under high rate epitaxial growth conditions.The results show that the difficulties to control the silicon epitaxial parameters at edge can be solved by means of modulating the susceptor height,controlling the distribution of heating power,pre-coating silicon on the susceptor,depositing intrinsic layer and so on.The high growth rate up to 6.6μm/min was successfully realized.