Experiments of Sub-Micron Superjunction Devices With Ultra-Low Specific On-Resistance

A sub-micron superjunction (SM SJ) device with ultra-low specific on-resistance ${R}_{\text {on},{sp}}$ is proposed and experimentally realized in this letter. The new device features a surface SM SJ with a mean ion implantation depth of 190 nm and a bulk curvature effect suppressing layer (CSL) with a junction depth of $3.7~\mu \text{m}$ . The highly doped SM SJ acts as a ultra-low resistance current path to reduce the specific on-resistance ${R}_{\text {on},{sp}}$ meanwhile the CSL shields the possible curvature effect for high breakdown voltage ${V}_{\text {B}}$ . Experiments of the SM SJ device demonstrated a significantly increased total N-type doping dose up to $9.7\times 10^{{12}}$ cm $^{-{2}}$ that is almost 10 times of the conventional RESURF dose. A measured low ${R}_{\text {on},{sp}}$ of 27.8 $\text{m}\Omega \cdot $ cm ² was observed under a ${V}_{\text {B}}$ of 622.6 V, realizing a high figure of merit FOM = ${V}_{{\text {B}}^{{2}}} / {R}_{\text {on},{sp}}$ of 13.94 MW/cm ² and a reduction of 62.2% when compared with the theoretical limit of the triple RESURF technology under the same ${V}_{\text {B}}$ .