Hysteresis in Lanthanide Aluminum Oxides Observed by Fast Pulse CV Measurement

Abstract

Oxide materials with large dielectric constants (so-called high-k dielectrics) have attracted much attention due to their potential use as gate dielectrics in Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). A novel characterization (pulse capacitance-voltage) method was proposed in detail. The pulse capacitance-voltage technique was employed to characterize oxide traps of high-k dielectrics based on the Metal Oxide Semiconductor (MOS) capacitor structure. The variation of flat-band voltages of the MOS structure was observed and discussed accordingly. Some interesting trapping/detrapping results related to the lanthanide aluminum oxide traps were identified for possible application in Flash memory technology. After understanding the trapping/detrapping mechanism of the high-k oxides, a solid foundation was prepared for further exploration into charge-trapping non-volatile memory in the future.

Investigation of anomalous capacitance-voltage behavior caused by interface dipoles and the effect of post-metal-annealing

“…The related current through the sample (i total ) was amplified by a current amplifier and then monitor by channel two (v CH2 ). The detailed working principle and the approach to the CV characteristics have been discussed in our previous research output [3]. …”

“…Figure 2(a) showed the original Voltage-Time (VT) data from both channel one and channel two of the oscilloscope. The pulse CV characteristic given in Fig.2 (b) was calculated using the following formula based on the VT data in Fig.2 (a) [3].…”

“…The replacement of SiO 2 with high-k dielectrics (dielectric constant larger than that of SiO 2 , 3.9)is a solution to the challenge. In MOSFET technology, SiO 2 was replaced by a hafnium-based high-k material in 2007 [2].When the high-k material is used, a smaller equivalent oxide thickness (EOT) is obtained compared to SiO 2 gate dielectric with same physical thickness [3].In other words, the gate dielectrics with small EOT can be obtained without the expense of an increase of the leakage current by the employment of high-k material. Therefore, a number of high-k materials, HfO 2 , ZrO 2 , Y 2 O 3 and their silicates, have been widely researched [4,5].…”

Effects of biased irradiation on charge trapping in HfO2 dielectric thin films

“…The small increase in loop width is likely due to the fact that more bias-induced electrons are injected into HfO 2 to neutralize the positive cyclic charges which are located in shallow traps in the HfO 2 . There is a fall in the capacitance value of the pulse CV measurement within the range of 1.5 V to 2 V. The phenomenon is mainly due to the response time of the oscilloscope and the capacitance charging and discharging issues [15]. …”

“…have already been reported in previous work [15]. The waveform of the applied gate pulse (CH1) and amplified output pulse (CH2) for pulse CV technique are shown in Fig.…”