1. A metal-oxide-semiconductor field-effect transistor (MOSFET) device, comprising:
a funnel-shaped trench having a flared rim etched in a semiconductor substrate,
the flared rim having an upper edge at a wider cross section trench opening at about a top surface of the semiconductor substrate and having a lower edge at a top opening of a narrower cross section trench body portion that terminates in the semiconductor substrate;
a gate electrode disposed in the funnel-shaped trench on a gate dielectric layer formed on the flared rim, the gate electrode having a split structure with a first gate electrode portion being separated from a second gate electrode portion by an insulator material; and
a source region, a gate region, and a drain region disposed in the semiconductor substrate,
the gate region abutting a lower portion of the flared rim, the drain region abutting a sidewall of the narrower cross section trench body portion with a top of the drain region being aligned with a lower edge of the gate electrode.
2. The MOSFET device of claim 1, wherein the flared rim has a substantially linear profile in cross-section between the upper edge of the flared rim and the lower edge of the flared rim.
3. The MOSFET device of claim 1, wherein the flared rim has a curved profile in cross-section between the upper edge of the flared rim and the lower edge of the flared rim.
4. The MOSFET device of claim 1, wherein the flared rim is flared at an angle of about 45 degrees to a perpendicular to the top surface of the semiconductor substrate.
5. The MOSFET device of claim 1, wherein the flared rim is flared at an angle of between 20 degrees and 80 degrees to a perpendicular to the top surface of the semiconductor substrate.
6. The MOSFET device of claim 1, wherein the lower edge of the gate electrode is at about the lower edge of the flared rim.
7. The MOSFET device of claim 1, wherein the gate electrode includes at least one of a polysilicon material, a cobalt silicide material, and a titanium silicide material.
8. The MOSFET device of claim 1, wherein the funnel-shaped trench has a depth greater than about 1 \u03bcm.
9. The MOSFET device of claim 1, further comprising a shield gate electrode disposed in the narrower cross section trench body portion, the shield gate electrode being insulated from and disposed below the gate electrode.
10. The MOSFET device of claim 1, further comprising a self-aligned source-metal contact.
11. The MOSFET device of claim 1, wherein the semiconductor substrate is a heavily doped n-type conductive substrate with a lightly doped n-type epitaxial over layer, and the funnel-shaped trench terminates within the lightly doped n-type epitaxial over layer.
12. The MOSFET device of claim 1, wherein the semiconductor substrate is a heavily doped p-type conductive substrate with a lightly doped p-type epitaxial over layer, the funnel-shaped trench terminates within the lightly doped p-type epitaxial over layer.
13. The MOSFET device of claim 1, wherein the first gate electrode portion is separated from the second gate electrode portion by about a width of the top opening of the narrower cross section trench body portion.
14. The MOSFET device of claim 1, wherein the gate electrode having an etched opening extending vertically therethrough to the top opening of the narrower cross section trench body portion.
15. The MOSFET device of claim 1, wherein the semiconductor substrate is made of a silicon-based material.
16. The MOSFET device of claim 14, wherein the etched opening is filled with the insulator material.
17. The MOSFET device of claim 14, wherein the semiconductor substrate is made of a silicon-based material.
18. A metal-oxide-semiconductor field-effect transistor (MOSFET) device, comprising:
a funnel-shaped trench disposed in a semiconductor substrate, the funnel-shaped trench having a flared rim and having a trench body disposed below the flared rim, the flared rim having a sidewall with a first slope and the trench body having a sidewall with a second slope different from the first slope;
a gate dielectric layer disposed in the trench on the flared rim;
a gate electrode disposed on the gate dielectric layer;
a source region abutting an upper portion of the flared rim;
a gate region abutting a lower portion of the flared rim; and
a drain region abutting a sidewall of the trench body, the drain region having a top aligned with a lower edge of the gate electrode.
19. The MOSFET device of claim 18, wherein the first slope is about 45 degrees to a perpendicular to a top surface of the semiconductor substrate.
20. The MOSFET device of claim 18, wherein the first slope is about between 20 degrees and 80 degrees to a perpendicular to a top surface of the semiconductor substrate.
21. The MOSFET device of claim 18, wherein the lower edge of the gate electrode is at about a lower edge of the flared rim.
22. The MOSFET device of claim 18, wherein the gate electrode includes at least one of a polysilicon material, a cobalt silicide material, and a titanium silicide material.
23. The MOSFET device of claim 18, further comprising a shield gate electrode disposed in the trench body below the flared rim, the shield gate electrode being insulated from the gate electrode.
24. The MOSFET device of claim 18, wherein the semiconductor substrate is a heavily doped conductive substrate with a lightly doped epitaxial over layer, the funnel-shaped trench terminates within the lightly doped epitaxial over layer.
25. The MOSFET device of claim 18, wherein the semiconductor substrate is made of a silicon-based material.
26. A metal-oxide-semiconductor field-effect transistor (MOSFET) device, comprising:
a trench in a semiconductor substrate, the trench having a flared rim, the flared rim extending down from a wider cross-section trench opening at about a top surface of the semiconductor substrate to a narrower cross-section trench body portion that terminates in the semiconductor substrate;
a gate electrode disposed in the trench on the flared rim;
a drain region in the semiconductor substrate, the drain region having a top aligned with about a lower edge of the gate electrode disposed in the trench on the flared rim;
a gate region disposed in the semiconductor substrate above the drain region; and
a source region disposed in the semiconductor substrate above the gate region, the source region including a dopant in a portion of the semiconductor substrate above a top edge of the gate electrode.
27. The MOSFET device of claim 26, wherein the gate electrode includes a polysilicon electrode disposed on a gate dielectric layer disposed on the flared rim.
28. The MOSFET device of claim 26, further comprising a shield gate electrode disposed in the trench body below the flared rim, the shield gate electrode being insulated from the gate electrode.
29. The MOSFET device of claim 26, wherein the semiconductor substrate is a heavily doped conductive substrate with a lightly doped epitaxial over layer, and the trench having the flared rim terminates within the lightly doped epitaxial over layer.
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. A composite comprising a heat-resistant fiber and a siloxane polymer:
2. The composite according to claim 1, wherein the siloxane polymer is a crosslinked siloxane polymer obtainable by polycondensing a siloxane compound mainly of the following formula (1):
(wherein n represents an integer of 2 to 10; R1, R2, R3 and R4 may be each the same or different, and represent a hydrogen atom or an alkyl group of 1 to 4 carbon atoms; and R2 and R4 may be each the same or different every repetition unit).
3. The composite according to claim 1, wherein the heat-resistant fiber is one or more kinds of fibers selected from the group consisting of a wholly aromatic polyamide fiber, a wholly aromatic polyester fiber, a polyparaphenylene benzobisoxazole fiber, a fluorine fiber, a carbon fiber, a glass fiber and a quartz fiber.
4. The composite according to claim 1, wherein the heat-resistant fiber is a polyparaphenylene terephthalamide fiber.
5. A process for preparing a composite comprising a heat-resistant fiber and a siloxane polymer, which comprises coating or impregnating a heat-resistant fiber with a solution containing a compound represented by the following formula (1):
(wherein n represents an integer of 2 to 10; R1, R2, R3 and R4 may be each the same or different, and represent a hydrogen atom or an alkyl group of 1 to 4 carbon atoms; and R2 and R4 may be each the same or different every repetition unit), a catalyst for curing the compound represented by the formula (1) and, optionally, reaction water, and curing the compound represented by the formula (1).
6. The process according to claim 5, wherein the solution further contains at least one kind of a compound selected from the group consisting of a compound represented by the formula (2):
(wherein R5, R6 and R7 may be each the same or different, and represent a hydrogen atom, an alkyl group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms or a C1-6alkoxy-C1-4alkyl group, and R8 represents an alkyl group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms or an aryl group of 6 to 20 carbon atoms, and one or more hydrogen atoms of each of said groups may be substituted with an epoxy group, a glycidyl group, an amino group, a methacryl group, an acryl group, an ureido group, a mercapto group or an isocyanate group directly or via an intervening group), a condensate in which two or more molecules of the compound represented by the formula (2) are condensed (provided that the compound represented by the formula (1) is excluded), a compound represented by the formula (3):
(wherein R9, R10, R11 and R12 may be each the same or different, and represent a hydrogen atom, an alkyl group of 1 to 10 carbon atoms or an alkenyl group of 2 to 10 carbon atoms, and among them, one or both of R10 and R12 may be an alkyl group of 1 to 10 carbon atoms, an alkenyl group of 2 to 10 carbon atoms or an aryl group of 6 to 20 carbon atoms, one or more hydrogen atoms of each of said groups may be substituted with an epoxy group or a glycidyl group directly or via an intervening group), and a condensate in which two or more molecules of the compound represented by the formula (3) are condensed.
7. A fiber-reinforced glass comprising a heat-resistant fiber and a siloxane polymer as a constituent component.
8. A heat-resistant fiber covered with a siloxane polymer.
9. The heat-resistant fiber according to claim 8, wherein the heat-resistant fiber covered with a siloxane polymer has a tape-like yarn form.
10. An aramid fiber covered with a siloxane polymer, characterized in that an aramid fiber containing moisture at an equilibrium moisture content or larger is impregnated or coated with a coating solution in which a compound represented by the formula (1), and an organic compound which is hydrolyzable and whose hydrolysat contains a metal serving as a catalyst for curing the compound are dissolved in a substantially anhydrous solvent, and the organic solvent is removed and, at the same time, the compound is cured utilizing the moisture in the aramid fiber as reaction water,
(wherein n represents an integer of 2 to 10; R1, R2, R3 and R4 may be each the same or different, and represent a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, and R2 and R4 may be each the same or different every repetition unit).
11. The composite according to claim 2, wherein the heat-resistant fiber is one or more kinds of fibers selected from the group consisting of a wholly aromatic polyamide fiber, a wholly aromatic polyester fiber, a polyparaphenylene benzobisoxazole fiber, a fluorine fiber, a carbon fiber, a glass fiber and a quartz fiber.
12. The composite according to claim 2, wherein the heat-resistant fiber is a polyparaphenylene terephthalamide fiber.