ASCENT Theme 1(B) Experiments and Modeling to Understand Growth of AlN Heater Spreaders and Switching and Endurance in HZO

Experiments and Modeling to Understand Growth of AlN Heater Spreaders and Switching and Endurance in HZO

Presenters: KJ Cho (UTD), Asif Khan (Georgia Tech), and Andrew Kummel (UCSD)

Date & Time: Oct 20, 2021  4:00pm and 8pm eastern 

Part 1: (Low T AlN and GaN)  Polycrystalline AlN can be grown at low temperature by sputtering or atomic layer annealing for use as a top or bottom heat spreader for backend or RF applications.  The role of ion bombardment is critical to provide surface diffusion of atoms at low temperature to get large grains; however, it is oxygen contamination which is the primary limit to high thermal conductivity.  Results will be shown for record thermal conductivity for low temperature thermal conductivity of AlN (in collaboration with Eric Pop of Stanford).  Results will also be shown for deposition of GaN by atomic layer annealing at 250C. 
Part 2:  (Lower Voltage HZO FeFETS) The are two limits on the current performance of HZO FeFETs:  high switching voltage and low endurance.  DFT models have been developed to understand the role of both dielectric interlayers in defect formation in HZO gate stacks as well as the role of tetravalent doping (Si, Ge, Ti, Ce) in lowering the switching voltages.  Experiments and models show removal of dielectric interlayers reduces the switching voltage and modeling also show doping by Si and Ge can reduce the switching voltage consistent with experiments showing lower switching voltage for HZO on Ge (due to Ge diffusion into HZO) than HZO on Si.  Recent experimental results elucidating the relation between the endurance of the memory window in the FEFET and the polarization of the ferroelectric layer in the same FEFET and the role of traps therein will also be discussed.

ASCENT Tasks: 
2776.058 - Novel Routes to ALD of Crystalline Materials at Low Temperature 
2776.059 -  DFT of Ferroelectric HfO2 and Related Compounds plus MIT Materials
2776.071 - Experimental Study of Defect Generation and Fundamental Limits of Endurance in Ferroelectric and Antiferroelectric H2O
2776.081 - DSSP: RoadMap for Thermal Boundary Resistance for AlN and Diamond RF Heat Spreaders 

This meeting is only available to the JUMP research community, such as Principal Investigators, Postdoc researchers, Students, and Industry/Government liaisons.