FARKLI B+ İMPLANTASYON KOŞULLARI İÇİN RADFET’LERİN ELEKTRİKSEL KARAKTERİZASYONUNUN TCAD BENZETİM PROGRAMI İLE İNCELENMESİ

Yıl 2017, Cilt: 22 Sayı: 2, 53 - 64, 20.08.2017

Ayşegül Kahraman Ercan Yılmaz

https://doi.org/10.17482/uumfd.335425

Öz

Bu çalışmada, RadFET’lerin kapı oksit tabakasına
implante edilmiş B⁺ iyonlarının V_th üzerine etkisi,
Silvaco TCAD benzetim programı ile incelenmiştir. 300 nm ve 400 nm
kalınlıklarında kapı oksite sahip RadFET’ler, tüm üretim adımları TCAD’e
tanıtılarak tasarlanmıştır. İmplantasyon öncesi ve sonrası V_th
değerleri, RadFET’lerin akım-gerilim (I_d-V_g) karakteristiklerinden
elde edilmiştir. Artan implantasyon enerjisi, V_th değerlerinin
düşmesine neden olmuştur. V_th değerinin sıfır olması, daha geniş
ölçülebilir doz aralığına sahip RadFET’lerin üretilmesi için önemlidir. Ancak,
implantasyon enerjisindeki sürekli artışla birlikte V_th, p-kanalı
oluşumu nedeniyle negatif voltaj değerlerinde gözlenmemiştir. 300 nm-RadFET
için en düşük V_th değeri, 6.5×10¹¹ iyon/cm² bor dozu
ve 72 keV’de, -1.082 V olarak bulunmuştur. 400 nm-RadFET için bu değer, 2.3×10¹¹
iyon/cm² bor dozu ve 106 keV’de, -1.139 V olarak elde edilmiştir.

Anahtar Kelimeler

RadFET, Üretim benzetimi, B+ implantasyonu, Eşik gerilimi, TCAD

Investigation of Electrical Characterization of RadFETs For Dİfferent B+ Implantation Conditions With TCAD Simulation Program

Öz

In this study, the effect of the B⁺
ions implanted to gate oxide layer of the RadFETs on V_th was
investigated by Silvaco TCAD simulation program. The RadFETs with the gate
oxide thicknesses of 300 nm and 400 nm were designed by introducing the all of
the RadFETs production steps to TCAD. The V_th values were obtained
from the current-voltage (I_d-V_g) characteristics of the RadFETs
before and after implantation. Increasing implantation energy caused the
reduction of the V_th values. The zero V_th value is
important to produce the RadFET with broader measurable dose range. However, V_th
was not observed in the negative voltages with continuous increment in the
implantation energy due to the p-channel formation. For the 300 nm-RadFET, the
lowest V_th value was found as -1.082 V for boron dose with 6.5×10¹¹
ions/cm² at 72 keV. This value for 400 nm-RadFET was obtained as
-1.139 V for boron dose with 2.3×10¹¹ ions/cm² at 106
keV.

Anahtar Kelimeler

RadFET, TCAD, Production simulation, B+ implantation, Threshold voltage, TCAD

Kaynakça

• Cho, S.J., Kim, W.T., Ki, Y.G., Kwon, S.I., Lee, S.H., Huh, H.D., Cho, K.H., Kwon, B.H. ve Kim, D.W. (2007) In Vivo Dosimetry with MOSFET Detector during Radiotherapy, World Congress on Medical Physics and Biomedical Engineering 2006, Springer (IFMBE Proceedings), COEX Seoul, 14, 1987-1989.
• Gavelle, M., Sarrabayrouse, G., Scheid, E., Siskos, E., Fragopoulou, M. ve Zamani, M. (2011) MOSFET with a boron-loaded gate as a low-energy neutron dosimeter, Radiation Physics and Chemistry, 80, 1437-1440. doi:10.1016/j.radphyschem.2011.08.001
• Holmes-Siedle, A. (1989) The use of RadFETs in radiation dose measurement: Report on three lots prepared for the US army: Final Technical Report, REM-FM-89-2, 1-38.
• http://ridl.cfd.rit.edu/products/manuals/Silvaco/athena_users1.pdf, Erişim Tarihi: 01.10.2016, Konu: ATHENA User’s Manual.
• http://www.sdram-technology.info/threshold-voltage-measurement.html, Erişim Tarihi: 05.05.2017, Konu: Threshold voltage for n-FET and p-FET.
• Jaksic, A., Ristic, G., Pejovic, M., Mohammadzadeh, A. ve Lane, W. (2002) Characterisation of radiation response of 400 nm implanted gate oxide RADFETs, Proc. 23 rd International Conference on Microelectronics (MIEL 2002), IEEE, Nis, 2, 727-730. doi: 10.1109/MIEL.2002.1003360
• Jornet, N.,Carrasco, P., Jurado, D., Ruiz, A., Eudaldo, T. ve Ribas, M. (2004) Comparison study of MOSFET detectors and diodes for entrance in vivo dosimetry in 18 MV X-ray beams, Medical Physics, 31, 2534-2542. doi: 10.1118/1.1785452
• Kahraman, A., Yilmaz, E., Kaya, S. ve Aktag, A. (2015) Effects of packaging materials on the sensitivity of RadFET with HfO2 gate dielectric for electron and photon sources, Radiation Effects and Defects in Solids, 170, 832-844. doi: 10.1080/10420150.2015.1118689
• Kim, S-J., Min, K-W. ve Ko, A. (2006) Use of a MOSFET for radiation monitoring in space and comparison with NASA trapped particle model, Journal of the Korean Physical Society, 48(4), 865-869.
• Kimoto, Y. ve Jaksic, A. (2004) RADFET utilization for spacecraft dosimetry, Proc. 24 th Internation Conference on Microelectronics (MIEL 2004), IEEE, Nis, 2, 657-659.
• Lindhard, J., Scharff, M. ve Schiott, H.E. (1963) Range concepts and heavy ion ranges, Matematisk-fysiske Meddelelser, 33, 1-42.
• Martίnez-Garcίa, M.S., Simancas, F., Palma, A.J., Lallena, A.M., Banqueri, J. ve Carvajal, M.A. (2014) General purpose MOSFETs fort he dosimetry of electron beams used in intra-operative radiotherapy, Sensors and Actuators A: Physical, 210, 175-181. doi: 10.1016/j.sna.2014.02.019
• Martίnez-Garcίa, M.S., Torres del RίO, J., Palma, A.J., Lallena, A.M. ve Jaksic, A. (2015) Comparative study of MOSFET response to photon and electron beams in reference conditions, Sensors and Actuators A: Physical, 225, 95-102. doi: 10.1016/j.sna.2015.02.006
• Mekki, J., Laurent, D., Glaser, M., Guatelli, S., Moll, M., Pia, M.G. ve Ravotti, F. (2009) Packaging effects on RadFET sensors for high energy physics experiments, IEEE Transactions on Nuclear Science, 56, 2061-2069. doi: 10.1109/TNS.2009.2014376
• Pejovic, M.M., Pejovic, M.M. ve Jaksic, A. (2012) Contribution of fixed oxide traps to sensitivity of pMOS dosimeters during gamma ray irradiation and annealing at room and elevated temperature, Sensors and Actuators A: Physical, 174, 85 – 90. doi: :10.1016/j.sna.2011.12.011
• Pejović, M., Ciraj-Bjelac, O., Kovačević, M., Rajović, Z. ve Ilić, G. (2013) Sensitivity of p-channel MOSFET to X-and Gamma-Ray Irradiation, International Journal of Photoenergy, 2013, 158403-1-6. doi: 10.1155/2013/158403
• Ramani, R., Russell, O’Breien, S.P. (1997) Clinical dosimetry using mosfets, International Journal of Radiation Oncology. Biology. Physics, 37, 959–964. doi: 10.1016/S0360-3016(96)00600-1
• Ristić, G., Golubović, S. ve Pejović, M. (1996) Sensitivity and fading of pMOS dosimeters with thick gate oxide, Sensors and Actuators, 51, 153-158. doi: 10.1016/0924-4247(95)01211-7
• Ristić, G.S., Pejović, M.M. ve Jakšić, A. (2007) Physico-chemical processes in metal-oxide-semiconductor transistors with thick gate oxide during high electric field stress, Journal of Non-Crystalline Solids, 353, 170-179. doi: 10.1016/j.jnoncrysol.2006.09.020
• Ristić, G.S., Vasović, N.D., Kovačević, M. ve Jakšić, A. (2011) The sensitivity of 100 nm RADFETs with zero gate bias up to dose of 230 Gy(Si), Nuclear Instruments and Methods in Physics Research B, 269, 2703-2708. doi: 10.1016/j.nimb.2011.08.015
• Rosenfeld, A. (2007) Electronic dosimetry in radiation therapy, Radiation Measurements, 41, S134-S153. doi: 10.1016/j.radmeas.2007.01.005
• Seon, J., Kim, S-J., Sung, B-I., Marri, S.A. ve Lee, S-H. (2010) A small space radiation monitor capable of measuring multiple ISD-VGS values of MOSFET, Journal of Nuclear Science and Technology, 47, 340-344. doi: 10.1080/18811248.2010.9711963
• Stanković, S.J., Ilić, R.D., Živanović, M., Janković, K.S. ve Lončar, B. (2012) Monte Carlo analysis of the influence of different packaging on MOSFET energy response to X-rays and gamma radiation, Acta Phys. Pol. A, 122, 655-658. doi: 10.12693/APhysPolA.122.655
• Wang, S., Liu, P. ve Zhang, J. (2013) Simulation of threshold voltage adjustment by B+ implantation for pMOS-RADFET application, 8th IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS), IEEE, Suzhou, 262-265.
• Wind, M., Beck, P. ve Jaksic, A. (2009) Investigation of the energy response of RadFET for high energy photons, electrons, protons, and neutrons, IEEE Transactions on Nuclear Science, 56, 3387-3392. doi: 10.1109/TNS.2009.2033060