Bulk Electron Accumulation LDMOS With Extended Superjunction Gate
Weizhong Chen, Haifeng Qin, Hongsheng Zhang, Zhengsheng Han
Abstract
An Extended Superjunction (SJ) Gate (ESG) Lateral Double-diffused Metal–Oxide Semiconductor (LDMOS) with full bulk electron accumulation in the drift is proposed, and the physical mechanism is investigated by the SENTAURUS. It features a Fin Gate including Planar Gate (PG) and ESG: the ESG is formed by the P-Pillar and two integrated back-to-back diodes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{2}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{D}_{{1}}$ </tex-math></inline-formula> , then the gate potential <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}$ </tex-math></inline-formula> is extended through the whole P-Pillar. Additionally, the gate oxide <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {oxide}}$ </tex-math></inline-formula> is inserted between the P- and N-Pillars of the SJ. At the ON-state, the 3-D electron channels are produced at the P-well by the Fin Gate, and the extra bulk accumulation effect is induced at the sidewalls of the N-Pillar by the positive <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}$ </tex-math></inline-formula> of the ESG, which can significantly decrease the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\mathrm{\scriptstyle {ON, SP}}}$ </tex-math></inline-formula> . At the OFF-state, the N- and P-Pillars deplete from each other through the gate oxide <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {oxide}}$ </tex-math></inline-formula> like the conventional SJ. The 3-D simulation results show that the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BV</i> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\mathrm{\scriptstyle {ON, SP}}}$ </tex-math></inline-formula> are 171 V and 0.49 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega \cdot \text {cm}^{{2}}$ </tex-math></inline-formula> , respectively. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FOM</i> is high up to 59.6 MW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which breaks through the silicon limit of the RESURF.