Novel BCD Process Platform with Integrated Self-Extracted JTE Trench Technology for EL Drivers ICs

A low cost silicon BCD technology in place of high cost SOI BCD technology for monolithic integrated EL driver ICs application is put forward. Several key technologies are presented. An advanced SEJTET termination technology was designed instead of the conventional PIOS isolation to obtain smaller chip area and protect HVICs from the occurrence of di/dt effect under PWM operation. Novel VDMOS/Resurf LDPMOS devices were developed compatibly to obtain the lowest , improve silicon utilization, and simplify key process steps. 1. Introduction In recent years, many portable consumer electronic products have been sold on the market, such as 3G~4G iPhone mobile. Electroluminescent lamps (EL) technology is widely used as the display application of liquid crystal and backlighting because of the physical thinness and light uniformity, generating low power consumption for illumination lamp load with capacitance structure, especially lower cost than that of LED products recently [1, 2]. The EL load is essentially a capacitor structure with phosphor sandwiched between the electrodes. Recently EL driver integrated with full-bridge stage has been mostly developed on thin HV-BCD SOI material because it can play an important role in withstanding high breakdown voltage and protect the cross-talk effect from the noise through the current path of silicon substrate, employing buried oxide with relative dielectric constant ( ) and shallow isolation from HV block and LV block. In general, high breakdown devices based on thin SOI are almost LDMOS with RESURF principle, rather than VDMOS [3]. However, the specific on resistance ( ) of the former is larger than that of the later due to large curvature radius of potential distribution. On the other hand, with rich color for humanity display, the large number EL capacitance loads need to be driven, which requires that device size and the cost increase proportionally once HV-BCD SOI technology is still preferable. Therefore, it is paramount to find out a standard technology for EL driver to reduce the whole cost. Silicon epitaxial BCD technology is a popular technology applied in Plasma Display Panel (PDP) display products [4, 5], but several aspects of isolation and HV block integration are not effectively solved. For conventional p-isolation, not only there exists self-doping effect to degrade seriously the performance of the device and circuit, but also p-isolation structure with large area brings about a lot of defects to reduce the yield of HVICs products during long-time thermal cycle [6]. In addition, the process steps for