Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
231 words
A method for manufacturing a self-aligned T-type gate, the method comprising the steps of: (1) forming an insulating layer, a first metal layer, and a first photoresist layer, and patterning the first photoresist layer; (2) selectively removing the first metal layer such that the first metal layer under the first photoresist pattern is under-cut cut in a mesa form to form a gate pattern, and selectively removing the insulating layer such that the insulating layer under the first metal layer is under-cut in the same form as the first metal layer so as to pattern ohmic electrode regions; (3) forming a second metal layer on the ohmic electrode regions to form ohmic electrodes and selectively removing the insulating layer to be unsymmetrical with respect to the center of the first metal layer; (4) forming a second photoresist layer on the entire surface inclusive of the first metal layer and selectively removing the second photoresist layer to expose the first metal layer inclusive of one of the ohmic electrodes; (5) forming a third photoresist layer on the entire surface inclusive of the exposed ohmic electrode, and exposing a surface of the first metal layer; and, (6) removing the first metal layer, selectively removing the insulating layer under the first metal layer to form a gate electrode region, and forming a third metal layer on the entire surface to form a T-type gate.
Claim 2
Independent Claim
231 words
A method for manufacturing a self-aligned T-type gate, the method comprising the steps of: (1) forming an insulating layer, a first metal layer, and a first photoresist layer, and patterning the first photoresist layer; (2) selectively removing the first metal layer such that the first metal layer under the first photoresist pattern is under-cut cut in a mesa form to form a gate pattern, and selectively removing the insulating layer such that the insulating layer under the first metal layer is under-cut in the same form as the first metal layer so as to pattern ohmic electrode regions; (3) forming a second metal layer on the ohmic electrode regions to form ohmic electrodes and selectively removing the insulating layer to be unsymmetrical with respect to the center of the first metal layer; (4) forming a second photoresist layer on the entire surface inclusive of the first metal layer and selectively removing the second photoresist layer to expose the first metal layer inclusive of one of the ohmic electrodes; (5) forming a third photoresist layer on the entire surface inclusive of the exposed ohmic electrode, and exposing a surface of the first metal layer; and, (6) removing the first metal layer, selectively removing the insulating layer under the first metal layer to form a gate electrode region, and forming a third metal layer on the entire surface to form a T-type gate.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1, wherein an etching selectivity of said insulating layer is different from that of said first metal layer.
Claim 4
Dependent Claim
29 words
The method as claimed in claim 1, wherein said first metal layer for the formation of the gate pattern is etched by employing a gas of a chlorine system.
Claim 5
Dependent Claim
30 words
The method as claimed in claim 1, wherein a gas of a CF 4 system is employed to etch the insulating layer for the formation of the ohmic electrode regions.
Claim 6
Dependent Claim
26 words
The method as claimed in claim 1, wherein, when the insulating layer is etched, an electron cyclotron resonance (ECR) equipment is utilized to decrease plasma damage.
Claim 7
Dependent Claim
23 words
The method as claimed is claim 1, wherein said second metal layer is made of one of AuGe, nickel (Ni), and gold (Au).
Claim 8
Dependent Claim
72 words
The method as claimed in claim 1, wherein the (6) step includes the steps of: removing the second photoresist layer until the surface of the first metal layer is exposed; removing the first metal layer, dry-etching the insulating layer, and removing the substrate by a predetermined depth by dry-etch and wet-etch; and, removing sharp portions of the second and third photoresist layers and forming the third metal layer for the T-type gate.
Claim 9
Dependent Claim
25 words
The method as claimed in claim 1, wherein said third metal layer is made of any one of titanium (Ti), platinum (Pt), and gold (Au).
Claim 10
Dependent Claim
26 words
The method as claimed in claim 1, wherein said insulating layer is patterned to be unsymmetrical with respect to the center of the first metal layer.
Claim 11
Dependent Claim
22 words
The method as claimed in claim 1, wherein said second photoresist layer is removed by an RIE process employing O 2 .
Claim 12
Dependent Claim
26 words
The method as claimed in claim 4, wherein, when the insulating layer is etched, an electron cyclotron resonance (ECR) equipment is utilized to decrease plasma damage.
Claim 13
Dependent Claim
22 words
The method as claimed in claim 7, wherein said second photoresist layer is removed by an RIE process employing O 2 .