To improve the total-dose radiation hardness,silicon-on-insulator （SOI） wafers fabricated by the separation-by-implanted-oxygen （SIMOX） method are modified by Si ion implantation into the buried oxide with a post ...To improve the total-dose radiation hardness,silicon-on-insulator （SOI） wafers fabricated by the separation-by-implanted-oxygen （SIMOX） method are modified by Si ion implantation into the buried oxide with a post anneal. The ID- VG characteristics can be tested with the pseudo-MOSFET method before and after radiation. The results show that a proper Si-ion-implantation method can enhance the total-dose radiation tolerance of the materials.展开更多
The hardening of the buried oxide （BOX） layer of separation by implanted oxygen （SIMOX） silicon-on-insulator （SOI） wafers against total-dose irradiation was investigated by implanting ions into the BOX layers. T...The hardening of the buried oxide （BOX） layer of separation by implanted oxygen （SIMOX） silicon-on-insulator （SOI） wafers against total-dose irradiation was investigated by implanting ions into the BOX layers. The tolerance to total-dose irradiation of the BOX layers was characterized by the comparison of the transfer characteristics of SOI NMOS transistors before and after irradiation to a total dose of 2.7 Mrad（SiO2）. The experimental results show that the implantation of silicon ions into the BOX layer can improve the tolerance of the BOX layers to total-dose irradiation. The investigation of the mechanism of the improvement suggests that the deep electron traps introduced by silicon implantation play an important role in the remarkable improvement in radiation hardness of SIMOX SOI wafers.展开更多
In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiat...In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiation of three bias conditions. It has been found experimentally that back gate threshold shift and leakage current were greatly reduced during irradiation for hardened transistors, comparing to control ones. It has been confirmed that the improvement of total-dose properties of SOI devices is attributed to the silicon nanocrystals (nanoclusters) in buried oxides introduced by ion implantation.展开更多
In this work, we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers. A transistors are made on the wafer implanted wit...In this work, we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers. A transistors are made on the wafer implanted with Si^＋ and then annealed in N2, and B transistors are made on the wafer without implantation and annealing. It is demonstrated experimentally that A transistors have much less back-gate threshold voltage shift △Vth than B transistors under X-ray total dose irradiation. Subthreshold charge separation technique is employed to estimate the build-up of oxide charge and interface traps during irradiation, showing that the reduced AVth for A transistors is mainly due to its less build-up of oxide charge than B transistors. Photo- luminescence （PL） research indicates that Si implantation results in the formation of silicon nanocrystalline （nanocluster） whose size increases with the implant dose. This structure can trap electrons to compensate the positive charge build-up in the buried oxide during irradiation, and thus reduce the threshold voltage negative shift.展开更多
This paper presents the design and implementation of a monolithic CMOS DC-DC boost converter that is hardened for total dose radiation.In order to improve its radiation tolerant abilities,circuit-level and device-leve...This paper presents the design and implementation of a monolithic CMOS DC-DC boost converter that is hardened for total dose radiation.In order to improve its radiation tolerant abilities,circuit-level and device-level RHBD（radiation-hardening by design） techniques were employed.Adaptive slope compensation was used to improve the inherent instability.The H-gate MOS transistors,annular gate MOS transistors and guard rings were applied to reduce the impact of total ionizing dose.A boost converter was fabricated by a standard commercial 0.35μm CMOS process.The hardened design converter can work properly in a wide range of total dose radiation environments,with increasing total dose radiation.The efficiency is not as strongly affected by the total dose radiation and so does the leakage performance.展开更多
文摘To improve the total-dose radiation hardness,silicon-on-insulator （SOI） wafers fabricated by the separation-by-implanted-oxygen （SIMOX） method are modified by Si ion implantation into the buried oxide with a post anneal. The ID- VG characteristics can be tested with the pseudo-MOSFET method before and after radiation. The results show that a proper Si-ion-implantation method can enhance the total-dose radiation tolerance of the materials.
基金Project supported by the National Fund for Distinguished Young Scholars （Grant No 59925205）, the Basic Research Program of Shanghai （Grant No 02DJ14069）, and the National Natural Science Foundation of China （Grant No 10305018）.
文摘The hardening of the buried oxide （BOX） layer of separation by implanted oxygen （SIMOX） silicon-on-insulator （SOI） wafers against total-dose irradiation was investigated by implanting ions into the BOX layers. The tolerance to total-dose irradiation of the BOX layers was characterized by the comparison of the transfer characteristics of SOI NMOS transistors before and after irradiation to a total dose of 2.7 Mrad（SiO2）. The experimental results show that the implantation of silicon ions into the BOX layer can improve the tolerance of the BOX layers to total-dose irradiation. The investigation of the mechanism of the improvement suggests that the deep electron traps introduced by silicon implantation play an important role in the remarkable improvement in radiation hardness of SIMOX SOI wafers.
文摘In this work, top and back gate characteristics of partially-depleted NMOS transistors with enclosed gate fabricated on SIMOX which is hardened by silicon ions implantation were studied under X-ray total-dose irradiation of three bias conditions. It has been found experimentally that back gate threshold shift and leakage current were greatly reduced during irradiation for hardened transistors, comparing to control ones. It has been confirmed that the improvement of total-dose properties of SOI devices is attributed to the silicon nanocrystals (nanoclusters) in buried oxides introduced by ion implantation.
文摘In this work, we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers. A transistors are made on the wafer implanted with Si^＋ and then annealed in N2, and B transistors are made on the wafer without implantation and annealing. It is demonstrated experimentally that A transistors have much less back-gate threshold voltage shift △Vth than B transistors under X-ray total dose irradiation. Subthreshold charge separation technique is employed to estimate the build-up of oxide charge and interface traps during irradiation, showing that the reduced AVth for A transistors is mainly due to its less build-up of oxide charge than B transistors. Photo- luminescence （PL） research indicates that Si implantation results in the formation of silicon nanocrystalline （nanocluster） whose size increases with the implant dose. This structure can trap electrons to compensate the positive charge build-up in the buried oxide during irradiation, and thus reduce the threshold voltage negative shift.
基金Project supported by the National Defense Pre-Research Project of China(No.51311050202)
文摘This paper presents the design and implementation of a monolithic CMOS DC-DC boost converter that is hardened for total dose radiation.In order to improve its radiation tolerant abilities,circuit-level and device-level RHBD（radiation-hardening by design） techniques were employed.Adaptive slope compensation was used to improve the inherent instability.The H-gate MOS transistors,annular gate MOS transistors and guard rings were applied to reduce the impact of total ionizing dose.A boost converter was fabricated by a standard commercial 0.35μm CMOS process.The hardened design converter can work properly in a wide range of total dose radiation environments,with increasing total dose radiation.The efficiency is not as strongly affected by the total dose radiation and so does the leakage performance.
