Memory system and operating method thereof

A method for operating a memory system, comprising:

• performing a problem-causing operation on a first memory block among memory blocks included in a plane, in which multi-bit data is stored in each cell;
• detecting remaining memory blocks, except the first memory block, in the plane, as being in a problem occurrence candidate group;
• receiving a read command for a second memory block of the problem occurrence candidate group;
• searching for a read voltage application order corresponding to the second memory block from a table;
• and
• performing a read operation on the second memory block by sequentially applying a plurality of read voltages according to the searched read voltage application order,
• wherein the problem-causing operation is a program operation or an erase operation,
• wherein the performing of the read operation includes:
• performing, in response to the read command immediately after the problem-causing operation, a first read operation on the second memory block based on a secondary set of the plurality of read voltages;
• and
• performing, in response to the read command immediately after a successful read operation set including the first read operation on the second memory block, a second read operation on the second memory block based on a primary set of the plurality of read voltages.

An operating method of a controller, the operating method comprising:

• controlling a memory device to perform a program operation or an erase operation on a first block;
• controlling, in response to a command immediately after the program or erase operation, the memory device to perform a first default read operation on a second block based on a secondary set of read voltages, the second block neighboring the first block;
• and
• controlling, in response to a command immediately after a successful read operation set including the first default read operation on the second block, the memory device to perform a second default read operation on the second block based on a primary set of read voltages,
• wherein the primary and secondary sets have different application orders of the read voltages.