voltage high

**High-Voltage CMOS and LDMOS Power Device Process** is **process technologies enabling transistors operating at voltages exceeding logic supply (5V to hundreds of volts) — enabling integrated power management and power output stages**. High-voltage CMOS and LDMOS (Laterally-Diffused MOSFET) devices enable integrated power management, switching power supplies, motor control, and RF power amplifiers on the same chip as logic. High-voltage device design addresses key challenges: breakdown voltage, on-state resistance, and switching speed tradeoffs. LDMOS is widely used for high-voltage applications. LDMOS structure uses laterally-diffused drain diffusion, creating extended drain region with lower doping providing higher breakdown voltage. Conventional MOSFET extended drain structure uses drift region of similar doping to substrate. Lateral diffusion (hence LDMOS) laterally extends drain under field oxide, achieving higher voltage capability than vertical extension. Extended drain length trades on-state resistance for voltage capability. Longer drain extensions increase voltage rating but increase on-state resistance. Design optimizes this tradeoff for application. Breakdown voltage determined by peak electric field in off-state. Field plates or gate-drain connections control field distribution. Multiple field plates with intermediate potentials reduce peak field. Floating field plates provide optimal field distribution. Floating ring structures in modern LDMOS provide excellent field control. Gate oxide in high-voltage devices must withstand peak field without breakdown. Multiple oxide thicknesses are typical — thin gate oxide for switching speed, thick oxide for extended drain region (field oxide). Edge termination at device perimeter controls surface electric field preventing premature edge breakdown. Guard rings at different potentials create smooth field transition. On-state resistance includes channel resistance, accumulation layer resistance, and substrate resistance. Each component is optimized — longer channel slightly increases performance, wider device decreases resistivity, larger contact area reduces accumulation resistance. Substrate contact engineering reduces substrate resistance. Thermal management is important — high-voltage operation dissipates power in resistive structures. Device scaling benefits switching speed but typically degrades voltage capability or increases resistance. Tradeoffs dominate design. Modern nodes integrate high-voltage with advanced logic, requiring mixed-oxide and mixed-voltage design. **High-voltage CMOS and LDMOS enable integrated power management and switching, with careful design of extended drain structures and field control enabling high-voltage, low-resistance operation.**