JPS6176968A - Screening testing device of semiconductor memory element - Google Patents

Abstract

PURPOSE:To execute effectively a screening test by using a line address input clock pin and a refresh pin of a semiconductor memory element having a self- refresh function. CONSTITUTION:A titled device is provided with a semiconductor memory element 1, a line address input clock pin RAS, a refresh pin REF, a power source supply line 3, signal lines 8, 9, etc. In this state, in case when the element 1 is a dynamic RAM having a self-refresh function, the potential of the pin RAS is set to a high level, and the potential of the pin REF is set to a low level, by which the element 1 executes a self-refresh operation. In this case, as for a voltage for setting the potential of the pin RAS to a high level, the same voltage as a power supply voltage in case when the element 1 is operated as an ordinary memory element can be applied, therefore, it is also possible that the signal line 8 is used in common with the supply line 3. Also, an energy of the element 1 is supplied through the signal line 8 from a power source 2, therefore, the test can be realized easily by an ordinary static burn-in device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor memory device screening test apparatus that can effectively perform screening tests with a simple configuration.

[Conventional technology]

Although the semiconductor memory market continues to expand, as is well known, semiconductor memories have a type of failure called early failure. This is because memory that contains manufacturing defects deteriorates and becomes defective in the early stages of use.In order to ship highly reliable memory products, it is necessary to operate the memory for a certain period of time before shipping, and to ensure that the memory that should deteriorate deteriorates. Screening T
e5t) must be implemented. As a method of operating a semiconductor memory device for this screening test, static burn-in (static burn-in) in which only electricity is applied is used.
Dynamic burn-in (Burn In) and dynamic burn-in (Dynamic Bur
n In).

FIG. 2 is a block diagram showing the configuration of a conventional static burn-in device. In the figure, (1) is a semiconductor memory element undergoing a screening test, and (2) is a block diagram that supplies electrical energy to the semiconductor memory element (1). power supply, (3
) is a power supply line serving as a path for electrical energy from the power source (2) to the semiconductor memory element (1).

Further, FIG. 3 is a block diagram showing the configuration of a conventional dynamic burn-in device. In this figure, the same reference numerals as in FIG. 2 indicate the same components, and a description thereof will be omitted. (4
) is a clock generation circuit, (5) is a clock signal line, (6
) is an address generation circuit, and (7) is an address signal line.

[Problem that the invention seeks to solve]

Generally, in the case of memory devices, voltage is often applied to the entire internal circuit only when a clock or address is applied from the outside. In order to carry out an effective screening test for the above-mentioned memory devices, it is necessary to use a dynamic burn-in apparatus as shown in FIG.

For the above reasons, dynamic burn-in equipment is often used in screening tests, but dynamic burn-in equipment requires clock generation circuits and address generation circuits, which complicates the equipment configuration and increases the cost of the equipment itself. The drawback was that it was expensive.

[Means for solving problems]

The present invention has been made in view of the above points, and a semiconductor memory element having a self-refresh function is provided with a row address capture clock pin and a refresh pin, voltages are applied to the row address capture clock pin and refresh pin, respectively, and the row address When the take-in clock pin is at a high level and the refresh pin is at a low level, the self-refresh function of the semiconductor memory element operates, and a screening test is performed by simply applying an external voltage during this operation.

[Function] In the present invention, the control operation of the semiconductor memory element by an external control signal and the operation of the self-refresh function are switched based on the potential difference between the row address capture clock pin and the refresh pin, and the external voltage is switched during the operation of the self-refresh function. Screening tests can be performed by simply applying voltage, making it possible to perform screening tests as effectively as dynamic burn-in equipment, which can sequentially perform screening tests on memory cells by specifying addresses using static burn-in equipment, which has a simple configuration and is inexpensive. becomes.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A screening test apparatus for semiconductor memory devices according to an embodiment of the present invention will be described below with reference to FIG. The same reference numerals as the constituent blocks of the semiconductor memory device screening test apparatus according to the present embodiment in FIG. In Figure 1 above,
(RAS) (RowAddress 5trobe
) is a row address capture clock pin, (REF) (Rif
(8) is the row address capture clock pin (RAS) that reactivates the memory cell.
) is a signal line that applies a high level potential to the refresh pin (REF), and (9) is a signal line that applies a low level potential to the refresh pin (REF) and has one end grounded. Note that the semiconductor memory element (1) is generally a dynamic RAM (Ra
Among the dynamic RAMs currently on the market17) are self-ref1/-/shi,
There is a function called "sh)", and when a voltage is applied to the input pin in a predetermined relationship while the power supply voltage is applied, the row address is automatically refreshed every 12 to 18g5 by a timer built in the dynamic RAM. , all memory cells are refreshed in 2 ms.

Next, the operation of this embodiment based on the above configuration will be explained. First, when the semiconductor memory element (1) is a dynamic RAM having a self-refresh function, the potential of the row address capture clock pin (RAS) is set to a high level, and the potential of the refresh pin (REF) is set to a low level. As a result, the semiconductor memory element (1) performs a self-refresh operation. Here, the voltage that sets the potential of the row address capture clock pin (RAS) to a high level can be the same voltage as the voltage #i when the semiconductor memory element (1) operates as a normal memory element. Therefore, it is also possible to share the signal line (8) with the power supply line (3). Furthermore, the semiconductor memory element (
The self-refresh operation 1) is performed by supplying operating energy from the power supply (2) through the signal line (8).

Therefore, the configuration of this embodiment shown in FIG. 1 can be easily realized with a normal static burn-in device. In the case of the configuration of this embodiment, normal dynamic burn-in is
Although the cycle time is slightly longer at 12g5 to 1B4s compared to the cycle time of approximately 10g5, approximately the same effect as that of the screening test can be obtained.

〔Effect of the invention〕

A semiconductor memory element having a self-refresh function is provided with a row address capture clock bin and a refresh pin, and voltages are applied to the row address capture clock pin and refresh pin, respectively, so that the first row address capture clock bin is at a high level and the refresh pin is at a low level. The self-refresh function of the semiconductor memory element operates when Based on this, it is possible to switch between the control operation of the semiconductor memory element using an external control signal and the operation of the self-refresh function, and perform a screening test only by applying an external voltage while the self-refresh function is in operation.
By specifying addresses using a simple and inexpensive static burn-in device, an effective screening test can be performed in the same way as a dynamic burn-in device that can sequentially perform a screening test on memory cells.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of a screening test device for semiconductor memory devices according to an embodiment of the present invention, FIG. 2 is a block diagram of a static burn-in device for performing conventional screening tests, and FIG. 3 is a block diagram of a conventional dynamic burn-in device. The block diagram of a burn-in device is shown. In the figure, (1) is a semiconductor memory element, (2) is a power supply, (3) is a power supply line, (8) and (9) are signal lines, (RAS) is a row address capture clock bin, (REF
) The beam is Frenshbin.

Claims (1)

[Claims] A semiconductor memory element having a self-refresh function is provided with a row address capture clock pin and a refresh pin, and voltages are applied to the row address capture clock pin and refresh pin, respectively, so that the row address capture clock pin becomes high level and the refresh pin becomes low level. 1. A screening test apparatus for a semiconductor memory device, characterized in that when the self-refresh function of the semiconductor memory device is activated, a screening test is performed by simply applying an external voltage during the operation.