Improved Charge-Trapping Characteristics of ZrO₂by Al Doping for Nonvolatile Memory Applications

Toward Low-Power Flash Memory: Prospect of Adopting Crystalline Oxide as Charge Trapping Layer

“…Typically amorphous high-k dielectrics are chosen as CTLs, however, their k values rarely exceed 25 [5][6][7][8]. Recently, phase transformation of a high-k dielectric from amorphous phase to crystalline one has attracted considerable interest since it provides an effective method to enhance the k value without compromising the band gap [11].…”

“…Furthermore, high-k CTL also shows the possibility to possess a larger ΔEc with respect to SiO2 tunnel dielectric so that the charge can be stored with more desirable retention due to higher barrier. Because of the promising properties, high-k CTL such as HfON [4], La2O3 [5], Si3N4/Al2O3/HfO2 [6], HfO2 [7], Al-doped ZrO2 mixture [8] have aroused great interest in the field of flash memory. Nevertheless, the operation voltage is rarely below 10 V and it still has much room to be reduced to obtain lower power consumption.…”

“…Since the high voltage for program/erase operation aggravates the power consumption of the core circuitry and peripheral circuitry, it is of paramount importance to further scale down the operation voltage by developing novel materials and structures that could be fully integrated into incumbent VLSI technology. As aforementioned progress in CTL evolution, although the introduction of high-k based CTLs effectively reduces the operation voltage, most reported high-k CTLs are of amorphous phase [4][5][6][7][8] and further reducing operation voltage while keeping high operation speed are required to suppress power consumption. Recently, crystalline oxide is extensively developed as a promising CTL and hold the great potential to scale the operation voltage down to less than 10 V. In this paper, how crystalline oxide in the form of high-k dielectric and semiconductor can be utilized in flash memory as the CTL to reduce the operation voltage and the mechanism to achieve this goal are reviewed.…”

Tuning the electrical performance and bias stability of a semiconducting SWCNT thin film transistor with an atomic layer deposited AlZrOx composite

“…It is easily seen that the binding energy of Al 2p of all AlZrO x lms are lower than that of Al 2 O 3 (74.8 eV). 35,36 Both Zr 3d and Al 2p peaks for AlZrO x thin lms shi to higher binding energy with increasing Al concentration. It is found that the leading contribution is the charge transfer contribution.…”

Comparative study of oxidizing ambient infused with varying nitrogen flow rates for fabrication of ternary nitrided AlZrO based MOS capacitor

“…While numerous research attempts in exploring high dielectric constant ( k ) metal oxides were proposed as the remedy to conventional silicon dioxide (SiO 2 ), in order to circumvent the leakage current issue endured by the relatively thinner SiO 2 , aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ) have stood out from the crowd to be the promising metal oxides worth for further investigation. Zirconium oxide although exhibits a high k value in the range of 20 to 25, 1 large band gap (5‐8 eV), 2,3 and good thermal stability, continuous breakthrough was hampered by its low crystallization temperature (500°C) 3‐5 . The ease of crystallization in ZrO 2 on the other hand was giving con as a high k metal oxide, owing to the formation of grain boundaries, which would serve as a leakage current path 5 .…”