Process of manufacturing a vertical dynamic random access memory device
First Claim
1. A process of manufacturing a vertical dynamic random access memory device comprising the steps of:
- (a) providing a substrate having a top surface;
(b) etching a device trench into the substrate, the device trench having a sidewall, a lower portion, and an upper portion;
(c) forming a signal storage node in the lower portion of the device trench, the signal storage node having a storage node conductor;
(d) forming a signal transfer device in the upper portion of the device trench, the signal transfer device having a first diffusion region coupled to the storage node conductor and extending from the sidewall of the device trench into the substrate, a bit line diffusion region formed in the substrate adjacent to the top surface of the substrate and adjacent to the sidewall of the device trench, a channel region extending in the substrate from the first diffusion region to the bit line diffusion region, a gate insulator coating the sidewall of the device trench above the storage node conductor and adjacent the substrate, and a gate conductor filling the device trench;
(e) coupling a bit line conductor to the bit line diffusion region;
(f) self-aligning a wordline conductor formed upon the gate conductor with the sidewall of the device trench.
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Accused Products
Abstract
A dynamic random access memory (DRAM) device. The DRAM device is formed in a substrate having a top surface and a trench with a sidewall formed in the substrate. A signal storage node is formed using a bottom portion of the trench and a signal transfer device is formed using an upper portion of the trench. The signal transfer device includes a first diffusion region coupled to the signal storage node and extending from the sidewall of the trench into the substrate a second diffusion region formed in the substrate adjacent to the top surface of the substrate and adjacent the sidewall of the trench, a channel region extending along the sidewall of the trench between the first diffusion region and the second diffision region, a gate insulator formed along the sidewall of the trench extending from the first diffusion region to the second diffusion region, a gate conductor filling the trench and having a top surface, and a wordline having a bottom adjacent the top surface of the gate conductor and a side aligned with the sidewall of the trench.
21 Citations
5 Claims
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1. A process of manufacturing a vertical dynamic random access memory device comprising the steps of:
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(a) providing a substrate having a top surface;
(b) etching a device trench into the substrate, the device trench having a sidewall, a lower portion, and an upper portion;
(c) forming a signal storage node in the lower portion of the device trench, the signal storage node having a storage node conductor;
(d) forming a signal transfer device in the upper portion of the device trench, the signal transfer device having a first diffusion region coupled to the storage node conductor and extending from the sidewall of the device trench into the substrate, a bit line diffusion region formed in the substrate adjacent to the top surface of the substrate and adjacent to the sidewall of the device trench, a channel region extending in the substrate from the first diffusion region to the bit line diffusion region, a gate insulator coating the sidewall of the device trench above the storage node conductor and adjacent the substrate, and a gate conductor filling the device trench;
(e) coupling a bit line conductor to the bit line diffusion region;
(f) self-aligning a wordline conductor formed upon the gate conductor with the sidewall of the device trench. - View Dependent Claims (2, 3)
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4. A process of manufacturing a vertical dynamic random access memory device comprising the steps of:
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(a) providing a substrate having a top surface;
(b) depositing a nitride layer upon the top surface of the substrate;
(c) etching a device trench into the substrate, the device trench having a sidewall, a lower portion, and an upper portion;
(d) forming a signal storage node in the lower portion of the device trench, the signal storage node having a storage node conductor;
(e) coating the storage node conductor with a trench-top insulator;
(f) forming a signal transfer device in the upper portion of the device trench, the signal transfer device having a first diffusion region coupled to the storage node conductor and extending from the sidewall of the device trench into the substrate, a bit line diffusion region formed in the substrate adjacent to the top surface of the substrate and adjacent to the sidewall of the device trench, a channel region extending in the substrate from the first diffusion region to the bit line diffusion region, a gate insulator coating the sidewall of the device trench above the storage node conductor, and a gate conductor filling the device trench to a level above the top surface of the substrate;
(g) depositing a photoresist;
(h) patterning the photoresist to expose the gate conductor;
(i) etching the gate conductor selective to nitride to form a wordline trench aligned with the sidewall of the device trench; and
(j) depositing a wordline conductor in the wordline trench having a sidewall aligned with the sidewall of the device trench regardless of whether the photoresist is patterned in alignment with the sidewall of the device trench. - View Dependent Claims (5)
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Specification