Semiconductor memory device and method of operating the same

A semiconductor memory device, comprising:

• a memory cell array including a plurality of memory cells to be programmed to any one of first to N-th program states distinguishable based on threshold voltages of the memory cells;
• a peripheral circuit configured to perform a program operation on the plurality of memory cells;
• and
• a control circuit configured to control the peripheral circuit to perform the program operation including at least two verify steps corresponding to a first program states group including at least one program state among the first to N-th program states, respectively until the memory cells to be programmed to the first program states group have passed program verifications during the program operation,
• wherein, if the memory cells to be programmed to the first program states group have passed the program verifications, the control circuit performs a reprogram operation for a second program states group including at least one program state among the first to N-th program states,
• wherein the at least two verify steps are verify steps that use a pre-verification voltage and a main verification voltage corresponding to the first program states group, and
• wherein the reprogram operation with respect to the memory cells to be programmed to the second program states group is performed using the main verification voltage of the second program states group.

A method of operating a semiconductor memory device including a plurality of memory cells to be programmed to any one of first to N-th program states distinguishable based on threshold voltages of the memory cells, the method comprising:

• performing a primary program operation including a plurality of verify steps being performed for a first program states group including at least one program state among the first to N-th program states and at least one verify step being performed for a second program states group including at least one program state among the first to N-th program states;
• and
• after the primary program operation, performing a secondary program operation including an additional verify step on the plurality of memory cells to be programmed to the second program states group,
• wherein each of the plurality of verify steps comprises a pre-verify step and a main verify step corresponding to each program state included in the first program states group, and
• the at least one verify step is performed using a verification voltage that is equal to or higher than a verification voltage of the main verify step for the first program states group.

A method of operating a semiconductor memory device including a plurality of memory cells to be programmed to any one of first to N-th program states distinguishable based on threshold voltages of the memory cells, the method comprising:

• performing a program operation by performing at least two verify steps corresponding to a first program states group including at least one program state among the first to N-th program states until the memory cells to be programmed to the first program states group have passed program verifications;
• and
• if the memory cells to be programmed to the first program states group have passed the program verifications, performing a reprogram operation for a second program states group including at least one program state among the first to N-th program states,
• wherein the at least two verify steps are verify steps that use a pre-verification voltage and a main verification voltage corresponding to the first states group, and
• wherein the reprogram operation with respect to the memory cells to be programmed to the second program states group is performed using the main verification voltage of the second program states group.