Surface state density evaluation using high-frequency MOS capacitance technique

Abstract

A computational method is described which permits accurate determination of oxide capacitance C, and snbstrate impurity concentration N A (or N I , ) from high-frequency capacitance-voltage (C-U) data of a MOS diode in order to evaluate surface state density accurately as a function of surface potential. Using simulated SiO,/p-Si devices with typical parameters of C, = 150 pF, N A = lox5 ~m -~, and the area A = 0.005026 em2 without, surface states, it is theoretically shown tha.t the energy range of 0 ,S E -Ev & 1 eV can be probed with considerable accuracy by the C-Udata with experinientally feasi ble precisions. Experimental results are also presented in order to show the feasibility of the procedure on actual devices with surface state densities ranging orders of magnitude Eiiie numerische Mct'hode wird beschrieben, die am Hochfrequenz-Kapazitats-Spannungs(C-U)-Daten fur eine MOS-Diode die genaue Bestimmung von Oxydkapazitat C,, und Substratdotierung Ark (oder N,) gestattet, die zur genauen Ableitung der Energievert'eilaiig der Oberflachenzustande als Funktion des Oberfliichenpotentials benutzt werden konnen. Durch die Verwendnng von simulierten SiO,/p-Si-MOS-Dioden ohne Oberflachenzustande, niit typischen Parametern von C,, = 150 pF, N A = loi5 und der Flache A = 0,00502G cni2 wird gezeigt, daB bei C-U-Daten mit im Experiment erreichbarer PrBzision der Energiebereich von 0 E -Ev ,S 1 eV mit vortrefflicher Genauigkeit, nntcrsuclit werden kann. Auch experimentelle Werte werden angegeben, um zu zeigen, daB die Methode fur verschiedene, uber mehrere Gro8enordnungen variierende Oberflachenzustnndsdichten angemandt werden liann.

Interface passivation of liquid‐phase crystallized silicon on glass studied with high‐frequency capacitance–voltage measurements

“…The determination of D it and Q IL,eff is based on the analysis of the measured C–V curve in comparison with the corresponding theoretical curve ( C th ) of an ideal MIS capacitor (i.e., D it = 0 and Q IL,eff = 0) as illustrated in Fig. .…”

“…The determination of D it and Q IL,eff is based on the analysis of the measured C-V curve in comparison with the corresponding theoretical curve (C th ) of an ideal MIS capacitor (i.e., D it ¼ 0 Table 1 as a function of the wave number (v) in the mid-infrared. Refractive indices at 633 nm n 633 nm are included on the right hand side of the figure. and Q IL,eff ¼ 0) [28][29][30][31] as illustrated in Fig. 4.…”

PECVD-AlOx/SiNx Passivation Stacks on Silicon: Effective Charge Dynamics and Interface Defect State Spectroscopy

“…For high frequency C-V measurements the analysis of such relaxations allows the identification of deviating capacitances, e.g. due to unstable charges, which may lead to errors in the determination of D it [26]. Capacitance relaxations are typically observed in the inversion region due to the generation or recombination of minority charge carriers [24] after each voltage step, depending on measurement direction.…”

“…To determine the contributions of the effective oxide charge density (Q ox,eff ) and of the interface defect state density (D it ) of the c-Si/AlO x /SiN x structures on the passivation quality we carried out 1 MHz C-V measurements. Their evaluation is based on the analysis of the measured C-V curve in comparison with the corresponding theoretical one (C th ) of an ideal MIS capacitor (D it = 0 and Q ox,eff = 0) [23][24][25][26]. The C-V curve is either measured in sweep mode or in relaxation mode.…”

Photoconductivity and optical properties of silicon coated by thin TiO2 film in situ doped by Au nanoparticles

“…Hf‐CV characteristics were recorded using a Keithley 590 CV Analyzer combined with a Keithley 230 Voltage Source. The determination of D it is based on the analysis of the measured CV‐curve in comparison with the theoretical one of an ideal metal‐oxide‐semiconductor (MOS) capacitor 25–28. From the voltage conservation rules, the interface traps charge can be derived and expressed as where C ox is the oxide capacitance, Q ox,eff the effective fixed oxide charge, U and U th are the overall MOS voltages with and without oxide and interface charges, respectively.…”