1.University of Chinese Academy of Sciences，Beijing 100049，China； 2.Institute of Microelectronics of Chinese Academy of Sciences，Beijing 100029，China； 3.Key Laboratory of Science and Technology on Silicon Devices，Chinese Academy of Sciences，Beijing 100029，China
Abstract： Silicon-based radio frequency field effect transistors have the advantages of excellent linearity, simple drive circuit, fast switching speed, excellent thermal stability, no secondary breakdown, etc., and have broad application prospects in HF, VHF and UHF bands. In view of the application requirements of the RF field effect transistors with broadband, high gain and high efficiency, based on the standard planar MOS process, the split gate structure was adopted and a silicon-based RF vertical double-diffused metal oxide semiconductor field effect transistor with working voltage of 28 V was developed by optimizing the structure and process parameters. In the frequency range from 30 MHz to 90 MHz, the device can achieve small signal gain greater than 19 dB, the continuous wave output power can reach 87 W at the frequency of 60 MHz, the power added efficiency up to 72.4%, has excellent radio frequency performance.
Key words : radio frequency；field effect transistor；split gate；high gain；broadband
0 引言
硅基射頻場(chǎng)效應(yīng)晶體管作為固態(tài)功率器件，與雙極型晶體管相比，具有線性度好、驅(qū)動(dòng)電路簡(jiǎn)單、開(kāi)關(guān)速度快、熱穩(wěn)定性好、沒(méi)有二次擊穿和可以多胞并聯(lián)輸出大功率等一系列優(yōu)點(diǎn)[1-2]，在高頻(HF)、甚高頻(VHF)和特高頻(UHF)波段(如移動(dòng)通信、廣播、超視距雷達(dá)、磁共振成像、射頻加熱和無(wú)線電接收器等領(lǐng)域)得到廣泛應(yīng)用[3-4]。近幾年來(lái)，雖然氮化鎵(GaN)器件市場(chǎng)發(fā)展迅速，但是由于GaN材料加工工藝復(fù)雜，成本較高，主要適用于3.5 GHz或更高頻段的高頻大功率應(yīng)用場(chǎng)合，而在較低頻段，硅基射頻垂直雙擴(kuò)散金屬氧化物半導(dǎo)體場(chǎng)效應(yīng)晶體管(Vertical Double-diffused Metal Oxide Semiconductor field effect transistor，VDMOS)由于成熟度和性價(jià)比更高而更具優(yōu)勢(shì)，因此，硅基射頻VDMOS主要應(yīng)用在低頻寬帶大功率和對(duì)可靠性要求較高的領(lǐng)域[5-7]。
