1. A method of fabricating a semiconductor device comprising:
forming a trench isolation pattern in a semiconductor substrate, wherein the trench isolation pattern protrudes from the semiconductor substrate;
forming a first spacer on sidewalls of the trench isolation pattern;
forming an oxidation control region by nitriding a surface portion of the semiconductor substrate exposed by the trench isolation pattern and the first spacer;
removing the first spacer to expose peripheral portions of the semiconductor substrate bounding the oxidation control region; and
oxidizing the exposed semiconductor substrate to form a dielectric pattern,
wherein a central region has a first average thickness Tc and wherein peripheral regions adjacent the central region have a second average thickness Tp, wherein Tp>Tc.
2. The method of fabricating a semiconductor device according to claim 1, wherein forming the trench isolation pattern further comprises:
forming a pre-mask pattern on the semiconductor substrate;
etching the semiconductor substrate using the pre-mask pattern as an etch mask to form a first opening that exposes first regions of the semiconductor substrate; and
forming a trench isolation layer filling the first opening.
3. The method of fabricating a semiconductor device according to claim 2, wherein forming the first spacer on the sidewall of the trench isolation pattern further comprises etching a portion of the pre-mask pattern to form the first spacer on the sidewalls of the trench isolation pattern and second openings that expose second regions of the semiconductor substrate.
4. The method of fabricating a semiconductor device according to claim 2, wherein forming a pre-mask pattern on a semiconductor substrate further comprises:
forming a pad oxide layer on the semiconductor substrate;
forming a hard mask layer on the pad oxide layer; and
patterning the pad oxide layer and the hard mask layer to form the pre-mask pattern.
5. The method of fabricating a semiconductor device according to claim 4, wherein the hard mask layer is formed from material exhibiting an etch selectivity relative to the pad oxide layer.
6. The method of fabricating a semiconductor device according to claim 5, wherein the hard mask layer comprises at least one of silicon nitride and silicon oxynitride.
7. The method of fabricating a semiconductor device according to claim 2, further comprising:
planarizing the trench isolation layer to expose an upper surface of the pre-mask pattern.
8. The method of fabricating a semiconductor device according to claim 1, further comprising:
forming a floating gate structure on the dielectric pattern;
removing an upper portion of the trench isolation pattern;
forming an insulating layer on the floating gate structure and residual portions of the trench isolation pattern; and
forming a control electrode on the insulating layer.
9. The method of fabricating a semiconductor device according to claim 8, wherein:
the insulating layer includes a composite layer having a silicon oxidesilicon nitridesilicon oxide (ONO) structure.
10. The method of fabricating a semiconductor device according to claim 8, further comprising:
forming second spacers on adjacent sidewalls of the floating gate structure.
11. The method of fabricating a semiconductor device according to claim 1, further comprising:
removing an upper portion of the trench isolation pattern;
forming a charge storing layer on the dielectric pattern and residual portions of the trench isolation pattern;
forming a blocking layer on the charge storing layer; and
forming a control gate structure on the blocking layer.
12. The method of fabricating a semiconductor device according to claim 1, wherein removing the first spacer further comprises removing a portion of the sidewalls of the trench isolation pattern.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An antenna assembly comprising:
an antenna including a first antenna element and a second antenna element bent from a strip-like metal sheet and discrete from the first antenna element, said first and second antenna elements being symmetrically formed with respect to a first axis; and
a coaxial cable disposed along or parallel with the first axis and including an inner conductor electrically connected with the first antenna element, and an outer conductor electrically connected with the second antenna element.
2. The antenna assembly as claimed in claim 1, wherein said second antenna element is shaped into a parabola extending along a direction leaving away from the first antenna element.
3. The antenna assembly as claimed in claim 2, wherein said first antenna element has a base face facing toward the second antenna element.
4. The antenna assembly as claimed in claim 3, wherein said first antenna element is made from a metal block, said base face of the first antenna element comprising a first face orthogonal to the first axis and a pair of second faces extending obliquely toward the second antenna element from opposite sides of the first face.
5. The antenna assembly as claimed in claim 3, wherein said first antenna element is bent from a metal plate and comprises a body portion and a base portion bent vertically from the body portion, said base face being formed on said base portion and comprising a first face orthogonal to the first axis and a pair of second faces extending obliquely toward the second antenna element from opposite sides of the first face.
6. The antenna assembly as claimed in claim 3, wherein said first antenna element is bent from a metal plate and includes a body portion having three edges and three base portions bent vertically from the three edges of the body portion, said three base portions respectively having a first face orthogonal to the first axis, and two second faces extending obliquely toward the second antenna element, said first face and the two second faces constituting said base face, with two slits defined between adjacent first and second faces.
7. The antenna assembly as claimed in claim 3, wherein said base face is orthogonal to the first axis.
8. The antenna assembly as claimed in claim 1, wherein said second antenna element comprises a head portion orthogonal to the first axis and a pair of shoulder portions extending obliquely from opposite sides of the head portion toward a direction leaving away from the first antenna element, and said first antenna element has a base face orthogonal to the first axis and facing toward the second antenna element.
9. The antenna assembly as claimed in claim 1, wherein said second antenna element lies in an imaginary plane coplanar or parallel with another imaginary plane in which said first antenna element lies.
10. An antenna assembly comprising:
a first antenna defining a center line in a longitudinal direction and a first height at a boundary area in a height direction perpendicular to said longitudinal direction;
a second antenna spaced from the boundary area, formed by a sheet metal, and bent in a symmetrical manner with regard to the center line, said second antenna defining a second height in said height direction similar to said first height; and
a coaxial cable extending along the center line and defining an outer conductor linked to the second antenna, and an inner conductor linked to the first antenna.
11. The antenna assembly as claimed in claim 10, wherein the second antenna is curved around the center line.
12. The antenna assembly as claimed in claim 10, wherein the first antenna defines a plurality of angled sections facing the second antenna.
13. The antenna assembly as claimed in claim 10, wherein the boundary area complies with a configuration of an adjacent area of the second antenna.