Investigation of hafnium-aluminate alloys in view of integration as interpoly dielectrics of future Flash memories

Photoconductivity of Hf-based binary metal oxides

“…Data were obtained through methods such as spectroscopic ellipsometry and electron energy loss spectroscopy. In these works the widening of the gap is reported to occur linearly with increasing Al content, [25][26][27] which seems to be in contradiction with results of the present study. However, leaving aside the possible processing-induced gap variations known for HfO 2 , 18,28,29 one may point out that in all these works on Hf:Al oxides the spectral dependences of optical or electron loss functions were fitted assuming a single bandgap value.…”

Tailoring the Electrical Properties of HfO2 MOS-Devices by Aluminum Doping

“…Most probably this level is due to (Figure 10b,c) assigned to AlO − bonding groups deriving from a breaking of the network component, and to antibonding Hf atom d-states that form the lowest conduction band of the alloy. 10 The existence of a 0.4−0.5 eV level in the HAH(36/5/36) sample could be explained by taking into account the difference in the doping approach between this sample and the HAHAH(24/2/24/2/24) sample. As mentioned in ref 40, Al is too small to be effectively incorporated into the fluorite lattice and the solubility of Al in all ZrO 2 /HfO 2 phases is relatively low leading to a segregation of Al 2 O 3 to form separate Al 2 O 3 phases (Figure 10b).…”

“…In particular, Hfaluminates and HfO 2 −Al 2 O 3 nanolaminates have been investigated for applications as charge storage and blocking oxide layers in charge trapping flash memories; 8,9 interpoly dielectrics in floating gate flash memories; 10 in high voltage charge storage devices for flat panel displays; 11 as dielectric layers integrated with III−V compound substrates for high electron mobility transistors; 12,13 ferroelectric memories; 14 and resistive switching devices. 15 One big challenge proves to be the varying demands on the high-k dielectrics for different fields of applications.…”

High work function metal gate and reliability improvement for MOS device by integration of TiN/MoN and HfAlO dielectric

“…For HfAlO dielectric with various Al contents, the EOT values are almost equal. As reported in the literature [17], the differences of dielectric constant for HfAlO with various Al contents are little. Hence, the EOT values are similar.…”