TN (tunnel nitrate)-SONOS (silicon oxide nitrate oxide silicon) memory with composite nitrogen-based dielectric tunneling layer

Abstract

The invention relates to the field of semiconductor memories, and discloses a TN (tunnel nitrate)-SONOS (silicon oxide nitrate oxide silicon) memory with a composite nitrogen-based dielectric tunneling layer. The TN-SONOS memory comprises a semiconductor substrate, a grid electrode and a dielectric laminate; the semiconductor substrate comprises a channel, a source terminal and a drain terminal, and the source terminal and the drain terminal are adjacent to the channel; the dielectric laminate is arranged between the grid electrode and the surface of the channel and comprises a tunneling layer, a charge trapping layer and a stopping layer, the tunneling layer is in contact with the surface of the channel, the charge trapping layer is laminated on the upper side of the tunneling layer, and the stopping layer is laminated on the upper side of the charge trapping layer and is in contact with the grid electrode; and the tunneling layer is the composite dielectric tunneling layer and comprises a first layer consisting of silicon oxynitride SiON(x), a second layer consisting of Si3N4 and a third layer consisting of silicon oxynitride, SiON(y), the first layer is in contact with the surface of the channel, the second layer is adjacent to the first layer, and the third layer is adjacent to the second layer. By the TN-SONOS memory, the performance of a SONOS nonvolatile memory is improved, and the TN-SONOS memory can be applied to extremely small memory devices with high quality.

Description

technical field [0001] The invention relates to the field of semiconductor memory, in particular to a TN-SONOS memory with a composite nitrogen-based dielectric tunneling layer. Background technique [0002] In the field of semiconductor memory, flash memory is a kind of non-volatile memory technology. Traditional flash memory uses floating gates as charge storage units. However, with the continuous development of flash memory technology, the storage density continues to increase, and the distance between floating gates If it is reduced, there will be mutual influence between the stored charges of adjacent floating gates, which hinders the increase of storage density for floating gate flash memory technology. The SONOS (silicon-silicon dioxide-silicon nitride-silicon dioxide-silicon) memory uses an insulating charge trapping layer to replace the floating gate, completely avoiding the interaction between the stored charges, and it also has its unique The ONO structure makes ...

AI Technical Summary

Problems solved by technology

With the continuous development of memory technology, in order to make the erasing speed reach the practical application, the thickness of the tunnel oxide layer must be less than 30? Retention capability will be reduced, thereby affecting the reliability of the memory

If a thicker tunneling layer is used, the large electric field required for the erasing operation will cause electrons to be injected from the gate through the barrier layer into the charge trapping layer, and the injection of gate electrons will neutralize the injection of holes, resulting in erase In addition to saturation, if the erase saturation is too large, the erasure of charges cannot be achieved at all

Therefore, the tunneling layer of traditional SONOS is gradually unable to meet the contradictory requirements of data writing and erasing speed and data static retention characteristics at the same time: because the tunneling layer is thick with silicon dioxide, it is difficult to meet the requirements for data writing and erasing speed. Thin tunneling layer silicon dioxide is difficult to meet the requirements for data static retention characteristics

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