Enhanced interface properties of diamond MOSFETs with Al2O3 gate dielectric deposited via ALD at a high temperature

The interface state of hydrogen-terminated(C-H)diamond metal-oxide-semiconductor field-effect transistor(MOSFET)is critical for device performance.In this paper,we investigate the fixed charges and interface trap states in C-H diamond MOSFETs by using different gate dielectric processes.The devices use Al_(2)O_(3) as gate dielectrics that are deposited via atomic layer deposition(ALD)at 80℃and 300℃,respectively,and their C-V and I-V characteristics are comparatively investigated.Mott-Schottky plots(1/C2-VG)suggest that positive and negative fixed charges with low density of about 10^(11)cm^(-2) are located in the 80-℃-and 300-℃deposition Al2O3 films,respectively.The analyses of direct current(DC)/pulsed I-V and frequency-dependent conductance show that the shallow interface traps(0.46 eV-0.52 eV and 0.53 eV-0.56 eV above the valence band of diamond for the 80-℃and 300-℃deposition conditions,respectively)with distinct density(7.8×10^(13)eV^(-1)·cm^(-2)-8.5×10^(13)eV^(-1)·cm^(-2) and 2.2×10^(13)eV^(-1)·cm^(-2)-5.1×10^(13)eV^(-1)·cm^(-2) for the 80-℃-and 300-℃-deposition conditions,respectively)are present at the Al2O3/C-H diamond interface.Dynamic pulsed I-V and capacitance dispersion results indicate that the ALD Al_(2)O_(3) technique with 300-℃deposition temperature has higher stability for C-H diamond MOSFETs.

Estimated prevalence and sociodemographic correlates of mental disorders in medical students of Hebei Province,China:A crosssectional study

BACKGROUND In China,the identification rate and treatment rate of mental disorders are low,and there are few surveys on the prevalence of mental disorders among college students using diagnostic tools such as Mini-International Neuropsychiatric Interview(MINI),so the prevalence and treatment of mental disorders among college students are unclear.AIM To estimate prevalence of mental disorders among medical students in Hebei Province,and provide guidance for improving their mental health.METHODS This was a cross-sectional study based on an Internet-based survey.Three levels of medical students in Hebei Province were randomly selected(by cluster sampling)for screening.Using the information network assessment system,the subjects scanned the 2D code with their mobile phones,clicked to sign the informed consent,and answered a scale.A self-designed general status questionnaire was used to collect information about age,gender,ethnicity,grade,and origin of students.The MINI 5.0.was used to investigate mental disorders.Data analysis was performed with SPSS software.Statistically significant findings were determined using a two-tailed P value of 0.05.RESULTS A total of 7117 subjects completed the survey between October 11 and November 7,2021.The estimated prevalence of any mental disorders within 12 mo was 7.4%.Mood disorders were the most common category(4.3%),followed by anxiety disorders(3.9%);15.0%had been to psychological counseling,while only 5.7%had been to a psychiatric consultation,and only 10%had received drug therapy in the past 12 mo.CONCLUSION Although the estimated prevalence of mental disorders in medical students is lower than in the general population,the rate of adequate treatment is low.We determined that improving the mental health of medical students is an urgent matter.