Method for programming nonvolatile memory cells with program and verify algorithm using a staircase voltage with varying step amplitude

A method for programming a memory cell, comprising:

• applying to a control terminal of said memory cell a first programming pulse train with pulse amplitude increasing in staircase fashion;
• and
• applying to the control terminal of said memory cell a second programming pulse train with pulse amplitude increasing in staircase fashion, in which an amplitude increment between one pulse and the next in said first programming pulse train is greater than an amplitude increment between one pulse and the next in said second programming pulse train;
• applying, to said control terminal of said memory cell and before said first programming pulse train, a third programming pulse train with pulse amplitude increasing in staircase fashion, the amplitude increment between one pulse and the next in said third programming pulse train being less than the amplitude increment between one pulse and the next in said first programming pulse train.

A method for programming a memory cell, comprising:

• applying to a control terminal of said memory cell a first programming pulse train with pulse amplitude increasing in staircase fashion;
• applying to the control terminal of said memory cell a second programming pulse train with pulse amplitude increasing in staircase fashion, in which an amplitude increment between one pulse and the next in said first programming pulse train is greater than an amplitude increment between one-pulse and the next in said second programming pulse train;
• and
• applying, to a first terminal of said memory cell and simultaneously with each one of said programming pulse trains applied to said control terminal, a respective programming pulse trains with constant pulse amplitude.

A method for programming a memory cell, comprising:

• applying to a control terminal of the memory cell a first train of pulses, each pulse of the first train having an amplitude increasing by a first step value over an amplitude of the preceding pulse;
• applying to the control terminal of the memory cell a second train of pulses, each pulse of the second train having an amplitude increasing by a second step value over an amplitude of the preceding pulse;
• measuring a threshold voltage of the memory cell;
• and
• transitioning from the first train of pulses to the second train of pulses when the threshold voltage exceeds a first threshold value.

A method for programming a memory cell, comprising:

• applying to a control terminal of the memory cell a first train of pulses, each pulse of the first train having an amplitude increasing by a first step value over an amplitude of the preceding pulse;
• applying to the control terminal of the memory cell a second train of pulses, each pulse of the second train having an amplitude increasing by a second step value over an amplitude of the preceding pulse;
• and
• measuring a threshold voltage of the memory cell.

A memory device, comprising:

• a memory cell;
• means for applying to a control terminal of the memory cell a first train of pulses, each pulse of the first train having an amplitude increasing by a first step value over an amplitude of the preceding pulse;
• means for applying to the control terminal of the memory cell a second train of pulses, each pulse of the second train having an amplitude increasing by a second step value over an amplitude of the preceding pulse;
• means for measuring a threshold voltage of the memory cell;
• and
• means for transitioning from the first train of pulses to the second train of pulses when the threshold voltage exceeds a first threshold value.