Method for forming semiconductor device
AssigneeNEC Corporation
InventorHiromitsu Hada
Life of this patent
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Abstract
A method is provided for forming an epitaxial silicon layer on a diffused region of a silicon substrate having an anisotropic ratio of more than 3:1 between the growth rate in the direction perpendicular to the substrate surface and the growth rate in the direction parallel to the substrate surface. The epitaxial silicon layer serves as a contact plug which does not contact an adjacent contact plug formed by the same process in order to obtain a reliable semiconductor memory device with a high throughput, which is free from short circuit failure.
Claims22
A method for forming a semiconductor device comprising the steps of forming a diffused region in a portion of a surface region of a semiconductor substrate made of a first material, and selectively growing a semiconductor layer made of the first material and formed on the diffused layer under a condition that a ratio of a growth rate in a first direction perpendicular to the surface of the semiconductor substrate to a growth rate in a second direction parallel to the surface of the semiconductor substrate is not lower than about 3:1.
A method for forming a semiconductor device comprising the steps of forming consecutively a gate oxide film and a gate electrode on a semiconductor substrate made of a first material, introducing impurity ions into a portion of a surface region of the semiconductor substrate by a self alignment with the gate electrode to form a diffused region, forming an insulating layer covering an entire surface other than at least a portion of the diffused region, anisotropically growing the first material on at least the portion of the diffused region to form a semiconductor layer under a condition that a growth rate in a first direction perpendicular to the surface of the semiconductor substrate is larger than a growth rate in a second direction parallel to the surface of the semiconductor substrate, forming an insulating layer at least on the semiconductor layer, and forming a conductive layer on the insulating layer.
A method for forming a semiconductor device including the steps of forming consecutively a first insulating film and a gate electrode on a semiconductor substrate, forming a second insulating film having a first surface in contact with at least on side of the gate electrode, introducing impurity ions in a region of the semiconductor substrate adjacent to a second surface of the second insulating film opposing said first surface in contact with said at least one side of the gate electrode to form a diffused region of a first conductivity type, forming a first selective epitaxial layer on the second surface of the second insulating film and on the diffused region, and forming a second selective epitaxial layer on the first selective epitaxial layer, wherein ratio of a growth rate of at least said first selective epitaxial layer in a first direction perpendicular to a surface of the semiconductor substrate to a growth rate in a second direction parallel to the surface of the semiconductor substrate is greater than 1.
A method for forming a semiconductor device including the steps of forming a diffused region in a portion of a surface region of a semiconductor substrate made of a first material, and selectively growing a semiconductor layer made of the first material and formed on the diffused layer under a condition that a growth rate in a first direction perpendicular to the surface of the semiconductor substrate is larger than a growth rate in a second direction parallel to the surface of the semiconductor substrate.
Dependencies are inferred from the claim text.