Research and Development on High Resolution TDC for Space Experiments

本研究旨在研究和开发基于我们的高分辨率TDC(Time-to-Digital Converter)技术的高能和空间实验测量LSI。这种大规模集成电路必须具有很高的温度、冲击和辐射可靠性。所开发的大规模集成电路计划用于2013年发射的比埃科伦坡水星探测器。去年在台积电CMOS0.18um上加工的两级锁相环测试芯片存在I/O缓冲区故障，未完全用于评估。然而，在OKI 0.15um SOI(绝缘体上硅)中加工的TEG(测试元件组)芯片在像素传感器和晶体管阵列中显示出良好的效果。它们在东北大学回旋加速器上被10^15(~100 Mrad)的质子束辐照，通过调节背栅电压，显示出足够的辐射硬度，可用于空间应用。SOI工艺有望成为未来大规模集成电路的主流技术，具有辐射硬度高、工作温度高、功耗低的特点。除了上述结果外，我们之前的TDC芯片(TMC304)在东芝0.3um CMOS中处理，安装在月球探测器Selene上。我们确信它将从月球上发送有价值的数据

This research has aimed for research and development of measurement LSI for high-energy and space experiments based on our high-resolution TDC (Time-to-Digital Converter) technology. This LSI must have high reliability for temperature, shock, and radiation. The developed LSI is planned for use in BepiColombo Mercury explorer which is planned on launch in 2013.A test chip of two stages PLL (Phase Locked Loop), processed last year in TSMC CMOS 0.18um, has a fault in I/O buffer area, and not fully used for evaluation. However, a TEG (Test Element Group) chip processed in OKI 0.15 um SOI (Silicon-On-Insulator) showed good results in pixel sensor and transistor array. They are irradiated by proton beam of 10^15 (〜100Mrad) at Tohoku University Cyclotron, and revealed enough radiation hardness for space use by adjusting back gate voltage.SOI process is expected to be main stream technology for future LSI, and has good characteristics of radiation hardness, high-temperature operation, and low power. These are especially preferable in high-energy and space experiments.In addition to above results, our previous TDC chip (TMC304), which was processed in Toshiba 0.3 um CMOS, was installed in lunar explorer SELENE. We are sure it will send valuable data from the moon