| The performance and reliability for high permittivity dielectric (high-k dielectric) based device is severely degenerated due to its high defect density and complex distribution. Thus, the high-k dielectric defect and its characterization methods is drawn great attention.Defect information of the nanoscale MOS device can not accurately characterized by conventional method such as capacitance-voltage, stress and sense. Pulse method or charge pump method can characterize gate oxide defect close to the channel, but the defect information away from channel can not acquired. Therefor a new high-k dielectric defect characterization method is urgent needed. Internal defect distribution in high-k dielectric can be obtained by low frequency noise based on carriers exchange mechanism between internal defect and channel carriers. Noise method should be more valid as noise spectra density significantly increases in nanoscale device. So, the low frequency method is researched and major task as follows:1The exchange mechanism between high-k dielectric defect and channel carriers is investigated. Double barriers and single well structure model for carriers exchange is established. Transmission coefficient which channel carriers tunnel to internal defect is gained based on transfer matrix method. Transmission coefficient appears significant oscillation, confirming the existence of mechanism.2Characteristic time constant of various kinds tunneling mechanism is researched. Resonant tunneling characteristic time constant model is created, and simulation result is agreement with theory.3Drain current low frequency noise model is established based multi stack unified noise model with resonant tunneling mechanism taken consideration and simulation result is correspondence to experiments.4The defect characterization method for high-k dielectric is studied. Defect distribution is characterized when defect parameter is extracted base on noise data, and verifies this method. |
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