Farklı kapı oksitli RadFET dozimetrelerinin ışınlama öncesi elektriksel karakteristiklerinin TCAD benzetim programı ile değerlendirilmesi

Abstract

Bu çalışmanın amacı, kapı oksiti yüksek-k’lı dielektriklerden oluşan RadFET dozimetrelerinin ışınlama öncesi eşik gerilimlerini belirlemek ve sonuçları, kapı oksiti SiO₂’den oluşan geleneksel sensörlerle kıyaslamaktır. Ayrıca çalışmada, farklı konsantrasyonlu, derinlikli ve genişlikli p⁺ bölgelerinin RadFET’lerin elektriksel karakteristiği üzerine etkileri de incelenmiştir. Bu amaçla, dozimetrelerin duyar bölgeleri olarak 400 nm kalınlığında yüksek-k’lı Al₂O₃, HfO₂ dielektrikleri ve SiO₂ kullanılmıştır. Sensörler, Silvaco TCAD benzetim programında tasarlanmıştır. p⁺ bölgelerinin uzunlukları, I_d-V_g karakteristiğini değiştirirken, bu bölgelerin derinlikleri ve belirli bir değere kadar konsantrasyonları elektriksel karakteristikte önemli bir rol oynamamıştır. SiO₂, Al₂O₃ ve HfO₂-RadFET’lerden elde edilen en düşük eşik voltajları sırasıyla, -5.22, -3.63 ve -3.10 V olarak bulunmuştur. Bu sonuçlar, yüksek-k dielektrikli RadFET’lerin, radyasyon testlerinin yapılması koşuluyla, daha geniş ölçülebilir doz aralığı açısından yeni nesil dozimetreler için gelecek vaat eden bir aday olduğunu göstermektedir.

Keywords

• RADFET,TCAD,Yüksek-k,Eşik voltajı

Evaluation of the pre-irradiation electrical characteristics of the RadFET dosimeters with diverse gate oxides by TCAD simulation program

Abstract

The aim of the present study is to determine the pre-irradiation threshold voltages of the RadFET dosimeters with gate oxide composed of high-k dielectrics and compare the results with the traditional sensors, the gate oxide of which is composed of SiO₂. The effects of the p⁺ regions with different concentration, depth and length on the electrical characteristic of the RadFETs were also investigated in the study. For these purposes, Al₂O₃, HfO₂ high-k dielectrics and SiO₂ with the thicknesses of 400 nm were used as the sensitive regions of the dosimeters. The sensors were designed in the Silvaco TCAD simulation program. While the lengths of the p⁺ regions changed the I_d-V_g characteristics of the RADFETs, the depths and concentrations until a certain value of these regions did not play an important role in electrical characteristic. The lowest threshold voltages obtained from the SiO₂, Al₂O₃ and HfO₂-RadFETs were found to be -5.22, -3.63, and -3.10 V, respectively. These results demonstrated that RadFETs with high-k dielectrics may be promising candidate for the new generated dosimeters in terms of broader measurable dose range providing their radiation tests. 

Keywords

• RADFET,TCAD,High-k,Threshold voltage

References

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