CS240502B1 - Wiring eliminating the influence of leakage currents and parasitic capacities on the quasi-static capacitance-voltage curve of the MIS structure - Google Patents

Abstract

The invention belongs to the field of electrical engineering and solves the connection eliminating the influence of leakage currents and parasitic capacitances on the quasi-static capacitance-voltage curve of the MIS structure. Its essence is that the generator is connected to the summing circuit, to which a recorder is also connected, via a resistance-capacitive measuring block and a current-voltage converter.

Description

240502

BACKGROUND OF THE INVENTION The present invention relates to a method for removing leakage currents and parasitic capacitances from a quasi static capacitance curve of an MIS structure.

Quasi-static method of measuring capacitance-voltage dependencies METAL - INSULA-TOR - SEMICOIDUCTOR metal - insulator - - semiconductor structures in the next time to obtain the dependence of differential] MIS structure capacity from stress to structure.

The principle of the method consists in measuring a small unidirectional current of the order 10 "12A, flowing to the structure as a consequence of the attached linearly increasing voltage. In the case of sufficiently slow variations on the structure, we get a graphical recording of the passing current and the voltage n of the structure t. The low-frequency capacitance-voltage dependence of the MIS structure. This method of measuring the low-frequency capacitance-voltage dependence of the MIS structures is more advantageous in terms of time and economy than the measurement of low-frequency capacitance-voltage dependence by the classical method of measurement. The differential capacitance of the MIS structure utilizes a capacitive bridge for very low frequencies, and the ohmic current is written simultaneously with the capacitive current of the MIS structure by the large current of the quasi-static method. capacitance-to-filament dependence is distorted.

The above mentioned drawbacks are solved by the connection eliminating the influence of leakage currents and capacitive capacities on the quasi-static capacitance-voltage curve of the MIS structure according to the invention, the principle of which is that the second voltage terminal of the generator is connected to the third terminal summation circuit, both to the first recorder terminal and to the resistive capacitance measuring block via the current voltage converter to the second summator terminal, the first voltage generator terminal being connected to the first summator terminal to which the fourth terminal is connected to the terminal type -ku recorder. Further, the first summation terminal is connected via a grounded first-to-ground resistor and the second resistor is a first resistor, and a non-inverting differential amplifier input, and a third resistor circuit terminal is connected via a grounded second resistor, further through a fourth resistor, and secondly. the resistor on the fourth summation terminal and on the inverting differential amplifier input. The advantage of the connection according to the invention is the constant counting of the interfering components - the parasitic capacitance and the leakage current of the total current, thus preventing the deformation of the capacitive-voltage curves of the MIS structure and increasing the accuracy of the quasi-static method several times.

In the accompanying drawing, there is shown a device for eliminating the influence of leakage currents and parasitic capacities on the quasi-static capacitance-voltage curve of the MIS structure. In the circuit, the second voltage terminal 19 of the generator 4 is connected, on the one hand, to the third terminal 3 of the summing circuit 15, on the other hand, to the other terminal x of the recorder 17 and secondly to the capacitor capacitance measuring block 5 via the current-voltage converter 6 to the terminals 2 of the summing circuit 15. First the voltage terminal 18 of the generator 4 is connected, for example, to the terminal 1 of the summation circuit 15, the fourth terminal 16 being connected to the second terminal y of the recorder 17. Further, the first terminal 1 of the summation circuit 15 is connected via a grounded first variable resistor 7 and through a second resistor 9, first, a resistor 8 and a non-inverting input of the differential amplifier 10, the output of which is connected to a fourth terminal 16 of the summing circuit 15, the second terminal 2 of the summing circuit 15 being connected via a third resistor 11 to an inverting input of the differential the amplifier 10 and then the third terminal 3 of the summing circuit 15 is connected via a second variable resistor 14, further across the quad resistor 12, first through fourth piatyodpor 13 to terminal 16 · sumačného circuit 15, and secondly to an inverting amplifier 10. The role vstupdiferenciálneho circuit is to obtain a strain of Uvyst which is proportional to only the capacitive prúduIcmis, flowing through the MIS structure.

The principle of operation is that at the output terminal 16 of the summing circuit 15, the voltage given by the relationship = U2 = K2U2 - K3U3 (I) is maintained. It can be shown that upon meeting the required conditions for voltage U1; U2, U3 and transfer constants Kb K2, K3 achieve the correct wiring activity.

For U-tension, the following applies: (Π)

The voltage U2 is proportional to the total MIS structure and the parasitic capacitance CPAR resistor 7, and through the second resistor 9 is the current-to-voltage transducer transmission constant 6.

For U2 voltage: U2 = K (Irpar + Icrar + Icmis) or U2 = K - ^ - + KCRAr -¾ KCmis

KARAR UL Úl (III)

For voltage U3 on input terminal 3 of summation circuit 15:

Claims (2)

240502 U3 = UG (IV) We assume that: K2.K = K3. Rpar (V) and Ki.K ‘= K2. K. CPAR (VI) wherein the tip of the measuring jig is triggered just above the measured MIS structure. Then the total current consists of flowing through the parasitic capacity CPAR. By turning the first variable resistor 7, we set the zero voltage to the fourth output terminal 16 of the summing circuit 15. Then, the measured MIS start-up of the measuring jig is connected and the generator 4, dUG ' ——— = 0. On the measured Then after substituting the relations (II), (IV) into the relation (I) we get: (III), Uvyst —K'Ki dUG dt K, K- Ug Rpar - K2K CPAR - - K2K Cmis K3.UG (VII) After adjusting and establishing relationships. (V), (VI) in relation (VII) we get: Uvyst - —KKK Cmis,. ° (VIII) Because = constant, we can write: Uvyst - K “. Cmis (IX) where K '= -K2K dUG dt The transmission constants Ki and K3 can be set using the first and second variable resistors 7 and 14. In practical operation, the transmission constant K i is found such that dUr is given by the generator 4 - --- · 0, the structure of MIS is the voltage UG - constant. The total current of the MIS structure is now only stored from the current flowing through the parity resistor Rpar of the MIS structure. By rotating the second variable resistor 14, I set the zero tension at the fourth terminal 16 of the sonic circuit 15. The summation circuit 15 thus set can be used to measure the capacitance-voltage dependencies of both the MIS structure and the entire series of samples. For very accurate measurements, it recommends setting the IQ and K3 transmission con- ditions in particular for each sample being measured. List of symbols: C - capacity F Cmk - capacity of structure MIS F Cpar - parasitic capacity of spike F Irrar - current flowing through parasitic resistance of MIS structure A Icpar - current flowing through parasitic capacitance of MIS A Icmis - capacitance current of structure MIS AK, K1 ( K2, K3 - transmission constants U - voltage V UG - voltage applied to the structureMIS V UR - generator output voltage V Uvyst - output voltage of summation circuit 15 V Ub U2, U3 - input voltage of summation circuit 15 V Rpar - parasitic resistance of MIS structure. OBJECT 1. A wiring eliminating the influence of leakage currents and parasitic capacities on a quasi-static capacitance-voltage curve of the MIS structure, characterized in that the second voltage terminal (19) of the generator (4) is connected to the third terminal (3) of the summation circuit (15) on the one hand, on the first clamp (x) of the writer (17) and on the other hand via the resistive capacitive measuring block (5) and via the flow-band converter (6) on the terminal (2) of the summing circuit (15), the first on the voltage terminal (18) of the generator (4) is connected to the first summation terminal (1) of water (15), the fourth terminal (16) of which is connected to the recorder terminal (s) (17). 2. Connection of the stage of claim 1, characterized in that the first terminal (1) of the summing circuit (15) is connected via a grounded first variable (7) and via a second resistor (9), on the other hand, the grounded first resistor (8) and the non-inverting the input of the differential amplifier (10), the output of which is connected to the fourth terminal (16) of the summation circuit (15), the second terminal (2) of the summation circuit 240502 du (15) being connected via the third resistor (11) to the inverting input of the differential the amplifier (10) and further the third terminal (3) of the scanning circuit (15) is connected via. a grounded second variable resistor (14) passing through a fourth resistor (12) and a second resistor (13) to a fourth terminal (16) of the summing circuit (15) and an inverting input of the differential amplifier ( 10). 1 sheet of drawings