Semiconductor memory

Abstract

The semiconductor memory has 8 memory banks that can be accessed simultaneously, and two fixed spare row decoders and two indexed spare row decoders are arranged in each memory bank. The fixed fuse devices correspond to the fixed spare row decoders, and two are provided in each bank. The index fuse device has nothing to do with the index spare row decoder. For example, 8 index fuse devices are set in each storage body to store the index data, which is used to determine which memory body the index standby row decoder is associated with. correspond.

Description

technical field [0001] The present invention relates to a semiconductor memory having redundant circuits for relief of defective memory cells. Background technique [0002] In general, a semiconductor memory has redundant circuits for improving product yield. When a defective memory cell exists in a normal cell array, the redundant circuit has a function of replacing the defective memory cell with a redundant memory cell in a spare memory cell array. [0003] The most common redundant circuit now adopts the method of replacing defective memory cells with redundant memory cells in relief units (replacement units). The so-called relief unit is a collection of storage units that are replaced while replacing a defective storage unit with a redundant storage unit. Relief units generally include memory cells connected to one or more word lines (row units), and memory cells connected to one or more bit line pairs (column units). [0004] In the case of using memory cells (rows) ...

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Problems solved by technology

In this way, the yield of the product cannot be improved.

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