Memory built-in self repair (MBISR) circuits/devices and method for repairing a memory comprising a memory built-in self repair (MBISR) structure

A self-repairing memory device comprising:

• at least one array of storage cells arranged in columns and rows, with each row comprising multiple words;
• at least one of redundant row or column elements for replacing rows or columns containing defective storage cells;
• at least one block of redundant word elements for replacing words containing defective storage cells without replacing the entire rows containing the words being replaced;
• and
• built-in self repair (BISR) circuitry configured to:
• conduct one of a column test and a row test comprising identifying and storing addresses of respective one of columns and rows having one or more defective storage cells, and overwriting stored addresses of one of the columns and rows having a first number of defective storage cells with addresses of one of columns and rows having a second number of defective storage cells, wherein the second number is greater than the first number;
• and
• replace at least one of a row and column having a stored address with a redundant row or column element and, after completion of the replacement of the at least one of a row and column by the redundant row or column element, to replace at least one word containing one or more defective storage cells with a redundant word element without replacing the entire row containing the at least one word.

A method for repairing a memory device having at least one array of memory cells arranged in rows and columns with each row further divided into a plurality of words, the method comprising:

• detecting a defective storage cell;
• conducting one of a column test and row test comprising identifying and storing addresses of respective one of columns and rows having greater than a predefined number of defective storage cells;
• replacing at least one of a row and column having a stored address with a redundant row or column;
• and thereafter
• replacing at least one word containing one or more defective storage cells with a redundant word without replacing the entire row containing the at least one word.

A self repairing memory device, comprising:

• at least one array of storage cells arranged in columns and rows, with each row comprising multiple words;
• at least one or redundant row and column elements for replacing respective one or rows and columns comprising defective storage cells;
• at least one block of redundant word elements for replacing words containing defective storage cells without replacing entire rows comprising the words being replaced;
• and
• built in self repair (BISR) circuitry configured to:
• conduct a column or row test comprising identifying and storing addresses of columns or rows having greater than a predefined number of defective storage cells;
• and
• replace at least one of a row and a column having a stored address with a redundant row or column element and, after completion of the replacement of the at least one of the row and column by the redundant row or column element, replace at least one word containing one or more defective storage cells with a redundant word element without replacing an entire row comprising the at least one word.