Abstract:
A stacked gate flash memory device and method of fabricating the same. A cell of the stacked gate flash memory device in accordance with the invention is disposed in a cell trench within a substrate and source and drain regions are formed in the same substrate side of the adjacent isolation trenches. Thus, the stacked gate flash memory device of the invention can achieve high integration of memory cells.
Abstract:
This invention relates to a method for detecting quantity variation of high purity liquid chemicals by way of detecting capacitance variation to determine the liquid level of liquid chemicals. Meanwhile, the ratio of the area of the smallest electrode of the capacitor to the distance between the electrodes is adjusted to magnify the capacitance so that a very small variation can be observed clearly. This invention also discloses a device to carry out this method.
Abstract:
A method of fabricating flash memory cell is described. The method includes the steps of providing a semiconductor substrate; forming a first gate insulating layer; forming a first conductive layer; forming a buffer layer; removing portions of the buffer layer to farm a floating gate insulating layer; forming a second conductive layer; removing portions of the first conductive layer and the second conductive layer, such that the second conductive layer forms conductive spacers having conductive tips situated at the tips, and the floating gate insulating layer, the floating gate and the first gate insulating layer are combined as a floating gate region; forming a second insulating layer; forming a third conductive layer; removing portions of the third conductive layer and the second insulating layer to form a control gate, a second gate insulating layer, a first opening and a second opening; forming a source region on the substrate; forming spacers; and forming a drain region on the substrate.
Abstract:
The present invention provides a process for fabricating a self-aligned split gate flash memory. First, a patterned gate oxide layer, a first patterned polysilicon layer, and a first patterned mask layer are successively formed on a semiconductor substrate, and a first insulating spacer is formed on their sidewalls. Then, shallow trench isolation (STI) is formed in the substrate using the first patterned mask layer and the first insulating spacer as a mask. Then, the first patterned mask layer and a part of the first insulating spacer are removed to expose the first patterned polysilicon layer. A floating gate region is defined on the first patterned polysilicon layer, and the surface of the first polysilicon layer in the floating gate region is selectively oxidized to form polysilicon oxide layer. Then, the polysilicon oxide layer is used as a mask to remove the underlying first polysilicon layer in a self-aligned manner to form a floating gate. Finally, an intergate insulating layer and a second patterned polysilicon layer as a control gate are succesively formed on the polysilicon oxide layer. The present invention forms a floating gate in a self-aligned manner, which can decreases critical dimension. When an oxidation process is conducted to form the above polysilicon oxide layer, the nitride liner layer and the insulating spacer formed in the trench protect the sides of floating gate from oxygen invasion. This prevents the line width of floating gate from size reduction. Current leakage is also be avoided.
Abstract:
A method for fabricating a DRAM cell having a crown-type capacitor over a semiconductor substrate is disclosed. The method includes steps of: (a) forming a transistor over the semiconductor substrate; (b) forming an insulating layer over the transistor; (c) selectively etching the insulating layer to form a contact opening; (d) forming a first conducting layer over the insulating layer and filling into the contact opening; (e) forming an etching stop layer and a mask layer over the first conducting layer; (f) pattering the mask layer to form a plurality of openings; (g) forming a dielectric spacer on the sidewall of the mask layer, and removing exposed portions of the etching stop layer; (h) anisotropically etching the mask layer and the first conducting layer by using the dielectric spacer as a mask, to expose, respectively, the etching stop layer and the insulating layer; (i) removing uncovered etching stop layer to expose the first conducting layer; (j) anisotropically etching the first conducting layer to a predetermined depth by using the dielectric spacer as a mask, thereby forming a crown-type storage electrode; (k) removing the dielectric spacer and the etching stop layer; (l) forming a dielectric layer over exposed portions of the storage electrode; and (m) forming a second conducting layer as an opposite electrode over the dielectric layer.
Abstract:
A floating gate and fabrication method thereof. A semiconductor substrate is provided, on which an oxide layer, a first conducting layer, and a patterned hard mask layer having an opening are sequentially formed. A spacer is formed on the sidewall of the opening. A second conducting layer is formed on the hard mask layer. The second conducting layer is planarized to expose the surface of the patterned hard mask layer. The surface of the second conducting layer is oxidized to form an oxide layer. The patterned hard mask layer and the oxide layer and the first conducting layer underlying the patterned hard mask layer are removed.
Abstract:
A stacked gate vertical flash memory and a fabrication method thereof. The stacked gate vertical flash memory comprises a semiconductor substrate with a trench, a source conducting layer formed on the bottom of the trench, an insulating layer formed on the source conducting layer, a gate dielectric layer formed on a sidewall of the trench, a conducting spacer covering the gate dielectric layer as a floating gate, an inter-gate dielectric layer covering the conducting spacer, and a control gate conducting layer filled in the trench.
Abstract:
A stacked gate flash memory device and method of fabricating the same. A cell of the stacked gate flash memory device is disposed in a cell trench within a substrate to achieve higher integration of memory cells.
Abstract:
A process for forming shallow trench isolation region with corner protection layer. A protection layer is formed within the opening that defines the isolation trench as part of the etching mask such that the etching rate of the protection layer is less than the mask layer and the pad insulating layer to the etchant used to remove the mask layer and pad insulating layer. The protection layer is partially removed and left adjacent to the shallow trench isolation region as a corner protection layer after removing the mask layer and pad insulating layer. Thus, the indentation next to the corner of the isolation region is avoided.
Abstract:
A floating gate with multiple tips and a fabrication method thereof. A semiconductor substrate is provided, on which a patterned hard mask layer is formed, wherein the patterned hard mask layer has an opening. A gate dielectric layer and a first conducting layer with a first predetermined thickness are formed on the bottom of the opening. A spacer is formed on the sidewall of the opening. A conducting spacer is formed on the sidewall of the spacer. The first conducting layer is etched to a second predetermined thickness. A multi-tip floating gate is provided by the first conducting layer and the conducting spacer. A protecting layer is formed in the opening. The patterned hard mask layer, the gate dielectric layer, a portion of the protecting layer, and a portion of the first spacer are etched to expose the surface of the first conducting layer.