A New Metal–Ferroelectric$(hboxPbZr_0.53hboxTi_0.47hboxO_3)$–Insulator$(hboxDy_2hboxO_3)$–Semiconductor (MFIS) FET for Nonvolatile Memory Applications

Abstract

Metal–ferroelectric–insulator–semiconductor (MFIS) field-effect transistors with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxPb(hboxZr_0.53, hboxTi_0.47)hboxO_3$</tex> ferroelectric layer and dysprosium oxide <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxDy_2hboxO_3$</tex> insulator layer were fabricated. The out-diffusion of atoms between <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxDy_2hboxO_3$</tex> and silicon was examined by secondary ion mass spectrometry profiles. The size of the memory windows was investigated. The memory windows measured from capacitance–voltage curves of MFIS capacitors and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$I_ DS$</tex> – <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_ GS$</tex> curves of MFIS transistors are consistent. The nonvolatile operation of MFIS transistors was demonstrated by applying positive/negative writing pulses. A high driving current of 9 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$muhboxA/muhboxm$</tex> was obtained even for long-channel devices with a channel length of 20 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$muhboxm$</tex> . The electron mobility is 181 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$hboxcm^2/hboxV cdot hboxs$</tex> . The retention properties of MFIS transistors were also measured.