Method of manufacturing charge storage device
First Claim
1. A method of manufacturing a charge storage device, comprising the steps of:
- providing a substrate;
forming a stacked insulation layer over the substrate, wherein the stacked insulation layer comprises a plurality of gradual material layers having a general formula bycz or axbycz, a, b, c represents different elements and the value of y changes from the bottom to the top of each gradual material layer, however, the value of the sum x+y+z remains fixed at 100%;
forming a mask layer over the stacked insulation layer;
patterning the mask layer and the stacked insulation layer to form an opening that exposes the substrate;
performing an etching process to form an irregular pattern on the sidewalls of the opening; and
forming a lower electrode on the sidewalls of the opening and over the substrate.
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Accused Products
Abstract
A method of manufacturing a charge storage device is provided. Utilizing the capacity for a precise control of the thickness and the silicon content of a deposited film in an atomic layer deposition process, a stacked gradual material layer such as a hafnium silicon oxide (HfxSiyOz) layer is formed. The silicon content is gradually changed throughout the duration of the HfxSiyOz deposition process. The etching rate for the HfxSiyOz layer in dilute hydrogen fluoride solution is dependent on the silicon content y in the HfxSiyOz layer. The sidewalls of the stacked gradual material layer are etched to form an uneven profile. The lower electrode, the capacitor dielectric layer and the upper electrode are formed on the uneven sidewalls of the stacked gradual material layers, the area between the lower electrode and the upper electrode is increased to improve the capacitance of the charge storage device.
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Citations
23 Claims
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1. A method of manufacturing a charge storage device, comprising the steps of:
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providing a substrate; forming a stacked insulation layer over the substrate, wherein the stacked insulation layer comprises a plurality of gradual material layers having a general formula bycz or axbycz, a, b, c represents different elements and the value of y changes from the bottom to the top of each gradual material layer, however, the value of the sum x+y+z remains fixed at 100%; forming a mask layer over the stacked insulation layer; patterning the mask layer and the stacked insulation layer to form an opening that exposes the substrate; performing an etching process to form an irregular pattern on the sidewalls of the opening; and forming a lower electrode on the sidewalls of the opening and over the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of manufacturing a charge storage device, comprising the steps of:
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providing a substrate; forming a stacked insulation layer over the substrate, wherein the stacked insulation layer comprises a plurality of gradual material layers fabricated using hafnium silicon oxide with a general formula HfxSiyOz such that the value of y changes from the bottom to the top of each gradual material layer; forming a mask layer over the stacked insulation layer; patterning the mask layer and the stacked insulation layer to form an opening that exposes the substrate; performing an etching process to form an irregular pattern on the sidewalls of stacked insulation layer exposed by the opening; and forming a lower electrode on the sidewalls of the stacked insulation layer exposed by the opening and over the substrate. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification