Backup line allocation apparatus, memory repairing apparatus, backup line allocation method, memory manufacturing method, and recording medium

A backup line allocation method for determining which fail lines, from among row-oriented fail lines and column-oriented fail lines containing fail bits in a memory provided with a plurality of backup lines, to allocate the backup lines to, comprising:

• for each fail bit contained in each fail hue, counting, a number of orthogonal fail bits, which is a number of fail bits in a fail line that includes the each fail bit and has an orientation that differs from the orientation of the each fail line, and storing the number of orthogonal fail bits associated with the each fail bit;
• calculating a weighting coefficient for each fail line based on the number of orthogonal fail bits of the fail bits contained in the each fail line, and storing the weighting coefficient associated with the each fail line;
• and
• determining which of the fail lines to allocate the backup lines to, based on the relative sizes of the weighting coefficients.

A non-transitory recording medium storing thereon a program that causes a computer to function as a backup line allocation apparatus that determines which fail lines, from among row-oriented fail lines and column-oriented fail lines containing fail bits in a memory provided with a plurality of backup lines, to allocate the backup lines to, the backup line allocation apparatus comprising:

• a bit counting section that, for each fail bit contained in each fail line, counts a number of orthogonal fail bits, which is a number of fail bits in a fail line that includes the each fail bit and has an orientation that differs from the orientation of the each fail line, and stores the number of orthogonal fail bits associated with the each fail bit;
• a weight calculating section that calculates a weighting coefficient for each fail line based on the number of orthogonal fail bits of the fail bits contained in the each fail line, and stores the weighting coefficient associated with the each fail line;
• and
• an allocating section that determines which of the fail lines to allocate the backup lines to, based on the relative sizes of the weighting coefficients calculated by the weight calculating section.