Design of high reliability RF-LDMOS by suppressing the parasitic bipolar effect using enhanced p-well and double epitaxy

A laterally diffused metal-oxide-semiconductor （LDMOS） device design with an enhanced p-well and double p-epitaxial structure is investigated for device ruggedness improvement while keeping its high device per- formance under high frequency. Based upon the device design, radio-frequency （RF） LDMOS transistors for GSM （global system for mobile communication） application have been fabricated by using 0.35/zm CMOS technolo- gies. Experimental data show that the proposed device achieves a breakdown voltage of 70 V, output power of 180 W. The RF linear gain is over 20 dB and the power added efficiency （PAE） is over 70% with the frequency of 920 MHz. In particular, it can pass the 20 ： 1 voltage standing wave ratio （VSWR） load mismatch biased at drain DC supply voltage of 32 V and output power at 10-dB gain compression point （P10dB）. The device ruggedness has been remarkably improved by using the proposed device structure.

Design of MCI single and symmetrical on-chip spiral inductors

In this paper,the MCI（multipath crossover interconnection）technique for octagon single and symmetrical spiral inductors has been presented to improve the quality factor.The metal wires of the single and symmetrical inductors formed by the top metal are divided into multiple segments according to the depth of the skin effects.The outermost path of the metal is crossover-interconnected to the innermost path by the underlayer metal and via The crossover technique makes the lengths of the total current paths between two ports approximately equal to each other.Therefore,the induced magnetic flux and resistance of each path can be balanced and the Q-factor of spiral inductors can be enhanced.The proposed MCI technique has been validated by the electromagnetic simulation with the 130-nm 1P6M SiGe BiCMOS process.For the devices with occupying areas of 240 240 μm^2,results of electromagnetic simulation show that about 24%improvement in the Q-peak（3.3 GHz）of the MCI single inductor as compared to conventional single inductors（3.1 GHz）,and about 88.1%improvement in the Q-peak（3.2 GHz）of the MCI symmetrical inductor as compared to conventional symmetrical inductors（1.8 GHz）.