SU767673A1 - Device for non-destructive testing and measurement of microbreakage voltage in dielectrical material of mds-structures - Google Patents

Description

An inlet is introduced to maintain the discharge of the energy accumulated on the test capacitor after the occurrence of a breakdown. Z.- - - ... - "-.

A disadvantage of the known device is the poor quality of monitoring of capacitors with a thin dielectric, caused by the insufficiently high speed of the shunt blocking control circuit, which consists of several devices connected in series, creating unacceptably large shunt blocking turn-on time to a local defect in the dielectric in which the breakdown develops, and to an increase in the probability of destruction of the structure. : In addition, because of the difference in the circuit of a unipolar tester voltage generator, the device does not provide the capacitor test with alternating voltage, which is necessary. Model: condensers or structures with. a thin dielectric, since the magnitude of the microprobe voltage in them often depends on the polarity of the applied voltage to the electrodes. . . The purpose of the invention is to improve the quality of non-destructive testing of MIS structures with a thickness of a dielect-. less than 1 micron .. 30

This goal is achieved by introducing a null-organ into the device, the input of which is connected to the test voltage generator, and the output to the switch connected between the generator and the test voltage. and the tested MDP structure, which is dual; with the test voltage generator through a serially connected amplifier amplifier micropro. Q bo and shunt block. V Such a device provides the flow of the test subject to the MIS-structure of an alternating test voltage and measurement of the microprobe voltage in the dielectric of the structure without its 4S destruction. .

The drawing shows a block diagram of the proposed device.

The device contains a test voltage generator 1, made in the form of a generator of unipolar pulses, a null organ 2, a switch 3, a test structure 4, an amplifier-detector. A probe 5, a shunt interlock 6, a voltage indicator micro 55 sample 7.

The principle of operation of the device is as follows.

The start-up unit 1 forms a unipolar test voltage pulse, which through the switching unit 3 is applied to the test sample 4. At the moment when the amplitude of the test voltage becomes equal to zero, the zero-organ 2 receives a signal coming in block comm. five

3, where the sample electrodes are re-switched. As a result, an alternating voltage is applied to the sample with a magnitude equal to twice the voltage amplitude generated by the generator 1. During a dielectric breakdown, the sample pulse enters the input of the amplifier 5 and through it turns on the shunt lock B, through which the MIS structure is discharged. The microprobe voltage value is output to the microprobe voltage indicator 7.

This device allows separating the voltage switching circuit on the MDP structure, which does not require high speed, since the test voltage generator generates pulses of such a form in order to provide a quasistatic charge of the structure capacitor (for example, triangular pulses), and. high-speed interlock circuit, which is connected directly to the test structure. The performance of the shunt interlock is increased by reducing the number of stages in the interlock control circuit (left microprobe detector amplifier). Moreover, the test voltage generator is designed as a generator of unipolar pulses (preferably positive polarity) it is possible to simplify microprobe detector circuit - to perform a shunt interlock on high-speed elements (high-voltage, high-voltage and -Along-two high-frequency transistors of the pnp type) , brought its response time to a value. This ensures that the quality control of VDP-structures with a thin dielectric and the ability to make it truly non-destructive is ensured. Finally, the introduction of the nullorgan controlling the switch provides the alternating test voltage from the generator of unipolar pulses to the structure, which also contributes to a more complete testing of the structure, i.e. improve quality control.

Claims (3)

1. Authors certificate of the USSR 533888, cl. GOI Tr 31/14, 1976 .. 2. Authors certificate of the USSR 401940, cl. G01 R 31/26, 1974. 3. Starodumov M.Hi, Tiflov V.I. A device for monitoring and measuring psfameter film structures. - Exchange of experience in the radio industry, 1974, no. 3, s. 63-64 (prototype).