Integration scheme for non-volatile memory on gate-all-around structure
A integrated device including a non-volatile memory (NVM) and a nanosheet field effect transistor (FET) and a method of fabricating the device include patterning fins for a channel region of the NVM and the FET. The method also includes depositing an organic planarization layer (OPL) and a block mask to protect the fins for the channel region of the FET, conformally depositing a set of layers that make up an NVM structure in conjunction with the channel region of the NVM while protecting the fins for the channel region of the FET with the OPL and the block mask, and removing the OPL and the block mask protecting the fins for the channel region of the FET. Source and drain regions of the NVM and the FET are formed, and a gate of the FET is formed while protecting the NVM by depositing another OPL and another block mask.
1. A method of performing integrated fabrication of a non-volatile memory (NVM) and a nanosheet field effect transistor (FET), the method comprising:
patterning fins for a channel region of the NVM and the nanosheet FET;
depositing an organic planarization layer (OPL) and a block mask to protect the fins for the channel region of the nanosheet FET;
conformally depositing a set of layers that make up an NVM structure in conjunction with the channel region of the NVM while protecting the fins for the channel region of the nanosheet FET with the OPL and the block mask;
removing the OPL and the block mask protecting the fins for the channel region of the nanosheet FET;
forming source and drain regions of the NVM and the nanosheet FET; and
forming a gate of the nanosheet FET while protecting the NVM by depositing another OPL and another block mask.
2. The method according to claim 1 , wherein the depositing the set of layers that make up the NVM structure includes conformally depositing silicon oxide nitride directly on the fins for the channel region of the NVM.
3. The method according to claim 2 , wherein the depositing the set of layers that make up the NVM structure includes conformally depositing hafnium dioxide on the silicon oxide nitride.
4. The method according to claim 3 , wherein the depositing the set of layers that make up the NVM structure includes conformally depositing silicon dioxide on the hafnium dioxide.
5. The method according to claim 1 , wherein the patterning the fins for the channel region of the NVM includes patterning alternating silicon and silicon germanium layers.
6. The method according to claim 1 , wherein the patterning the fins for the channel region of the NVM includes patterning a silicon germanium layer.
7. The method according to claim 1 , further comprising performing an isotropic etch of the fins for the channel region of the NVM following the depositing the OPL and the block mask to protect the fins for the channel region of the nanosheet FET and prior to the conformally depositing the set of layers that make up the NVM structure.
8. The method according to claim 1 , further comprising forming contacts to the source and drain regions of the NVM and the nanosheet FET.
9. The method according to claim 1 , further comprising patterning polysilicon above the channel region of the NVM, wherein the polysilicon is part of the NVM structure along with silicon in the channel region of the NVM.
10. The method according to claim 9 , further comprising forming contacts to the polysilicon.