Compatibility of silicon gates with hafnium-based gate dielectrics

Maximizing performance for higher K gate dielectrics

“…First, it should be noted that HfO 2 was only preferred to ZrO 2 because it was slightly more stable against forming silicides during the deposition of the poly-Si gate electrodes from silane. 41,42 However, now that metal gates are used, it is advantageous to turn back to ZrO 2 instead of HfO 2 because ZrO 2 has a higher K than HfO 2 ͑Ref. 43͒ while having almost the same band offsets.…”

Electrical and materials properties of AlN/ HfO2 high-k stack with a metal gate

“…Hafnium dioxide, HfO 2 , and hafnium silicate, Hf x Si (1 − x) O 2 , are promising candidates. However, these materials have some difficulty when used with metal gates due to interactions between the Hf-based dielectrics and metal or polysilicon gates affecting threshold voltage and the CMOS integration requires a p-type and n-type metal oxide semiconductor field effect transistor so that appropriate work functions must be engineered [1][2][3][4].…”

The influence of Coulomb centers located in HfO2/SiO2 gate stacks on the effective electron mobility

“…4,5 The so-called high-materials are proposed to maintain the same value of gate capacitance but with thicker layer than that used with SiO 2 insulator in order to reduce the gate leakage current. [12][13][14][15][16] However, interfacing these insulators with silicon is a major challenge. [6][7][8][9][10][11] Besides having a sufficiently large permittivity, the dielectric insulating the gate electrode from the Si substrate must fulfill critical requirements not detailed here but well explained in the articles of Robertson 4 and Locquet et al 5 Among the large number of high-dielectrics, the family of hafnium-oxide-based materials such as HfO 2 is one of the most studied due to its high thermal stability and low leakage current.…”