摘要:
A method includes forming a first layer of gate material over a semiconductor substrate; forming a hard mask layer over the first layer; forming an opening; forming a charge storage layer over the hard mask layer and within the opening; forming a second layer of gate material over the charge storage layer; removing a portion of the second layer and a portion of the charge storage layer which overlie the hard mask layer, wherein a second portion of the second layer remains within the opening; forming a patterned masking layer over the hard mask layer and over the second portion, wherein the patterned masking layer defines both a first and second bitcell; and forming the first and second bitcell using the patterned masking layer, wherein each of the first and second bitcell comprises a select gate made from the first layer and a control gate made from the second layer.
摘要:
A method for forming a semiconductor device includes forming a first plurality of nanocrystals over a surface of a substrate having a first region and a second region, wherein the first plurality of nanocrystals is formed in the first region and the second region and has a first density; and, after forming the first plurality of nanocrystals, forming a second plurality of nanocrystals over the surface of the substrate in the second region and not the first region, wherein the first plurality of nanocrystals together with the second plurality of nanocrystals in the second region result in a second density, wherein the second density is greater than the first density.
摘要:
A method of making a semiconductor device on a semiconductor layer includes forming a select gate, a recess, a charge storage layer, and a control gate. The select gate is formed have a first sidewall over the semiconductor layer. The recess is formed in the semiconductor layer adjacent to the first sidewall of the select gate. The thin layer of charge storage material is formed in which a first portion of the thin layer of charge storage material is formed in the first recess and a second portion of the thin layer of charge storage material is formed along the first sidewall of the first select gate. The control gate is formed over the first portion of the thin layer of charge storage material. The result is a semiconductor device useful a memory cell.
摘要:
A method of making a semiconductor device on a semiconductor layer includes forming a select gate, a recess, a charge storage layer, and a control gate. The select gate is formed have a first sidewall over the semiconductor layer. The recess is formed in the semiconductor layer adjacent to the first sidewall of the select gate. The thin layer of charge storage material is formed in which a first portion of the thin layer of charge storage material is formed in the first recess and a second portion of the thin layer of charge storage material is formed along the first sidewall of the first select gate. The control gate is formed over the first portion of the thin layer of charge storage material. The result is a semiconductor device useful a memory cell.
摘要:
A method includes forming a first layer of gate material over a semiconductor substrate; forming a hard mask layer over the first layer; forming an opening; forming a charge storage layer over the hard mask layer and within the opening; forming a second layer of gate material over the charge storage layer; removing a portion of the second layer and a portion of the charge storage layer which overlie the hard mask layer, wherein a second portion of the second layer remains within the opening; forming a patterned masking layer over the hard mask layer and over the second portion, wherein the patterned masking layer defines both a first and second bitcell; and forming the first and second bitcell using the patterned masking layer, wherein each of the first and second bitcell comprises a select gate made from the first layer and a control gate made from the second layer.
摘要:
Embodiments include a split-gate non-volatile memory cell that is formed having a control gate and a select gate, where at least a portion of the control gate is formed over the select gate. A charge storage layer is formed between the select gate and the control gate. The select gate is formed using a first conductive layer and a second conductive layer. The second conductive layer is formed over the first conductive layer and has a lower resistivity than the first conductive layer. In one embodiment, the first conductive layer is polysilicon and the second conductive layer is titanium nitride (TiN). In another embodiment, the second conductive layer may be a silicide or other conductive material, or combination of conductive materials having a lower resistivity than the first conductive layer.
摘要:
A floating gate memory cell has a floating gate in which there are two floating gate layers. The top layer is etched to provide a contour in the top layer while leaving the lower layer unchanged. The control gate follows the contour of the floating gate to increase capacitance therebetween. The two layers of the floating gate can be polysilicon separated by a very thin etch stop layer. This etch stop layer is thick enough to provide an etch stop during a polysilicon etch but preferably thin enough to be electrically transparent. Electrons are able to easily move between the two layers. Thus the etch of the top layer does not extend into the lower layer but the first and second layer have the electrical effect for the purposes of a floating gate of being a continuous conductive layer.
摘要:
A semiconductor storage cell includes a first source/drain region underlying a first trench defined in a semiconductor layer. A second source/drain region underlies a second trench in the semiconductor layer. A first select gate in the first trench and a second select gate in the second trench are lined by a select gate dielectric. A charge storage stack overlies the select gates and a control gate overlies the stack. The DSEs may comprise discreet accumulations of polysilicon. An upper surface of the first and second select gates is lower than an upper surface of the first and second trenches. The control gate may be a continuous control gate traversing and running perpendicular to the select gates. The cell may include contacts to the semiconductor layer. The control gate may include a first control gate overlying the first select gate and a second control gate overlying the second select gate.
摘要:
A virtual ground memory array (VGA) is formed by a storage layer over a substrate with a conductive layer over the storage layer. The conductive layer is opened according to a patterned photoresist layer. The openings are implanted to form source/drain lines in the substrate, then filled with a layer of dielectric material. Chemical mechanical polishing (CMP) is then performed until the top of the conductive layer is exposed. This leaves dielectric spacers over the source/drain lines and conductive material between the dielectric spacers. Word lines are then formed over the conductive material and the dielectric spacers. As an alternative, instead of using a conductive layer, a sacrificial layer is used that is removed after the CMP step. After removing the sacrificial portions, the word lines are formed. In both cases, dielectric spacers reduce gate/drain capacitance and the distance from substrate to gate is held constant across the channel.
摘要:
A method forms a split gate memory cell by providing a semiconductor substrate and forming an overlying select gate. The select gate has a predetermined height and is electrically insulated from the semiconductor substrate. A charge storing layer is subsequently formed overlying and adjacent to the select gate. A control gate is subsequently formed adjacent to and separated from the select gate by the charge storing layer. The charge storing layer is also positioned between the control gate and the semiconductor substrate. The control gate initially has a height greater than the predetermined height of the select gate. The control gate is recessed to a control gate height that is less than the predetermined height of the select gate. A source and a drain are formed in the semiconductor substrate.