The silicon micro-strip detector was fabricated by MEMS (Micro Electro Mechanical Systems) techniques[1].According to the application requirement and the process parameters, a large amount of B+ ions at 40 keV and1.51014 ions/cm2 have been implanted into the wafers. It is found that more than 50% of the micro strips cannotform a functional P-N junction. Based on the suggestion of simulation results, the process of stratified implantationwas then applied with the following procedures. B+ ions were firstly implanted into the wafer at 40 keV, 21014ions/cm2, and then sequentially implanted at 20 keV, 21014 ions/cm2 into the same wafers. Preliminary testresults show that over 95% of the silicon micro-strips in this batch have a perfect P-N junction with a reverse bodyresistance larger than 500 MΩcm. The energy resolution for 5.156 MeV particles of 239Pu source is about 0.8%or even less, as shown in Fig. 1. The structure of the detectors is therefore definitely different from the designeddevices (Fig. 2(a)) shown in Fig. 1, which is more like a P-P+-N structure as shown in Fig. 2(b).
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