Semiconductor memory device and method for testing the same
AssigneeKabushiki Kaisha Toshiba
InventorHiroshi Maejima
Life of this patent
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Abstract
A semiconductor memory device is provided which can apply a redundancy circuit replacement program to cells by a DS testing in a parallel testing state. That is, in this semiconductor memory device, when the redundancy circuit replacement is effected on an electrically programmable nonvolatile memory device, an internal circuit is so provided as to detect a defect chip retrievable on a DS tester while being in a parallel testing state as well as address information contained in the defect chip and, by doing so, it is possible to achieve the redundancy circuit replacement.
Claims21
A semiconductor memory device comprising:
- an address comparing circuit configured to make a comparison between a chip specifying address applied from an outside and a chip address programmed in a first nonvolatile memory element;
- a control circuit configured to control an activating state of an internal circuit included in the semiconductor memory device by using a result of comparison;
- and
- a test mode which activates the address comparing circuit and control circuit.
A method for testing a semiconductor memory device using a memory wafer formed by the ending of a wafer process and a tester for testing a plurality of memory chips on the memory wafer in a parallel testing state, the plurality of memory chips each having an internal circuit for allowing a redundancy circuit replacement, the method comprising:
- allowing a first nonvolatile memory element which is formed in the respective memory chip to be programmed with a chip address of the corresponding memory chip;
- testing the plurality of memory chips in a parallel testing state;
- making a comparison between the chip address of the respective memory chip and an externally applying chip specifying address of the chip retrievable with a redundancy circuit replacement and detecting a chip retrievable, in a parallel testing state, with the redundancy circuit replacement;
- and
- allowing programming to be done on a second electrically programmable nonvolatile element in the internal circuit with the redundancy circuit replacement.
Dependencies are inferred from the claim text.