Buried channel array transistors enable fast and high-density integrated devices.The depth of the PN junction and carrier dynamics at the depletion layer in silicon wafers have a crucial influence on their performance...Buried channel array transistors enable fast and high-density integrated devices.The depth of the PN junction and carrier dynamics at the depletion layer in silicon wafers have a crucial influence on their performance and reliability.Therefore,rapid and non-contact/non-destructive inspection tools are necessary to accelerate the semiconductor industry.Despite the great efforts in this field,realizing a technique to probe the junction depth and carrier dynamics at the PN junction inside wafers remains challenging.Herein,we propose a new approach to access PN junctions embedded in wafers using terahertz(THz)emission spectroscopy.THz emission measurements and simulations demonstrate that the amplitude and polarity of THz emissions reflect the junction depth and carrier dynamics at the PN junctions.It allows us to evaluate the junction depth non-destructively with nanometer-scale accuracy,surpassing the limits of traditional techniques.Laser-induced THz emission spectroscopy is a promising method for the sensitive and non-contact/non-destructive evaluation of Si wafers and will benefit the modern semiconductor industry.展开更多
The end effect on the output voltage of a twin-wire depth probe was investigated both theoretically and ex- perimentally.It was found that the contribution of the end of the probe to the output voltage depends upon th...The end effect on the output voltage of a twin-wire depth probe was investigated both theoretically and ex- perimentally.It was found that the contribution of the end of the probe to the output voltage depends upon the distance between the boundary and the end of the probe and the geometrical configuration of the probe. By mounting a piece of plate to the end of the electrodes,the end effect can be reduced.However,the size of the plate required to eliminate completely this effect is much larger than that usually mounted on commercially available probes.Comparison between theoretical and experimental results was made.Reasonable agreement was obtained.展开更多
Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases （MMPs） secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tis...Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases （MMPs） secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups： group I consisted of 20 periodontally healthy subjects （controls） while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth （PPD）, clinical attachment level （CAL）, gingival index （GI）, and plaque index （PI）. Around 3 ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA （Windows version 6） software. Salivary MMP-8 levels of groups I and II were 190.91 ± 143.89 ng/ml and 348.26± 202.1 ng/ml, respectively. The MMP-8 levels and periodontal status （PPD, CAL, GI, and PI） of groups I and II showed positive and significant correlations （for PPD, r = 0.63, P 〈 0.001; for CAL, r = 0.54, P 〈 0.001; for GI, r = 0.49, P 〈 0.001; and for PI, r = 0.63, P 〈 0.001）. The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.展开更多
基金M.T.acknowledges support by JSPS KAKENHI Grant No.JP23H00184F.M.acknowledges support in part by Grantin-Aid for JSPS Fellows Grant No.23KJ1475 and Program for Leading Graduate Schools:“Interactive Materials Science Cadet Program”.
文摘Buried channel array transistors enable fast and high-density integrated devices.The depth of the PN junction and carrier dynamics at the depletion layer in silicon wafers have a crucial influence on their performance and reliability.Therefore,rapid and non-contact/non-destructive inspection tools are necessary to accelerate the semiconductor industry.Despite the great efforts in this field,realizing a technique to probe the junction depth and carrier dynamics at the PN junction inside wafers remains challenging.Herein,we propose a new approach to access PN junctions embedded in wafers using terahertz(THz)emission spectroscopy.THz emission measurements and simulations demonstrate that the amplitude and polarity of THz emissions reflect the junction depth and carrier dynamics at the PN junctions.It allows us to evaluate the junction depth non-destructively with nanometer-scale accuracy,surpassing the limits of traditional techniques.Laser-induced THz emission spectroscopy is a promising method for the sensitive and non-contact/non-destructive evaluation of Si wafers and will benefit the modern semiconductor industry.
文摘The end effect on the output voltage of a twin-wire depth probe was investigated both theoretically and ex- perimentally.It was found that the contribution of the end of the probe to the output voltage depends upon the distance between the boundary and the end of the probe and the geometrical configuration of the probe. By mounting a piece of plate to the end of the electrodes,the end effect can be reduced.However,the size of the plate required to eliminate completely this effect is much larger than that usually mounted on commercially available probes.Comparison between theoretical and experimental results was made.Reasonable agreement was obtained.
文摘Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases （MMPs） secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups： group I consisted of 20 periodontally healthy subjects （controls） while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth （PPD）, clinical attachment level （CAL）, gingival index （GI）, and plaque index （PI）. Around 3 ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA （Windows version 6） software. Salivary MMP-8 levels of groups I and II were 190.91 ± 143.89 ng/ml and 348.26± 202.1 ng/ml, respectively. The MMP-8 levels and periodontal status （PPD, CAL, GI, and PI） of groups I and II showed positive and significant correlations （for PPD, r = 0.63, P 〈 0.001; for CAL, r = 0.54, P 〈 0.001; for GI, r = 0.49, P 〈 0.001; and for PI, r = 0.63, P 〈 0.001）. The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.
