What is claimed is:
1. A foldable knife comprising:
a handle including two spaced openings therethrough and two resilient pieces on two opposite sides, each resilient piece having one end coupled to the handle and the other end spaced from the handle, the other end of each resilient piece being slightly curved upward to form a stop;
two opposite blades pivotably coupled to forward and rear ends of the handle respectively, each blade having a cutting edge, a pivot member pivotably coupled to the handle, and a latch in a rear end, the stop being engaged with the latch when the blade is fully extended so as to lock the blade in an opened position; and
a protective element disposed between the openings and on a surface of the handle being pivotably coupled to the blade.
2. The foldable knife of claim 1, wherein the protective element is an elongate projection and has a first height.
3. The foldable knife of claim 2, wherein the protective element comprises two lengthwise grooves each facing either cutting edge so as to has a section of substantially T and in a closed position of the knife, the cutting edge of each blade is substantially received in the groove.
4. The foldable knife of claim 1, wherein the protective element is comprised of a plurality of equally spaced risers each having a second height.
5. The foldable knife of claim 4, wherein each riser comprises two lengthwise grooves each facing either cutting edge so as to has a section of substantially T and in a closed position of the knife, the cutting edge of each blade is substantially received in the groove.
6. The foldable knife of claim 5, wherein a spacing between any two adjacent risers has a length to prevent a hand of a user from being hurt by the cutting edges while holding the knife.
7. The foldable knife of claim 1, wherein the cutting edge of one of the blades is formed of a series of sharp teeth.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-34. (canceled)
35. A semiconductor device comprising:
a substrate;
a semiconductor layer provided in a part of the substrate;
a gate insulator film provided on the semiconductor layer;
a gate electrode provided on the gate insulator film; and
n-type source and drain regions provided in regions at both sides of the gate electrode of the semiconductor layer,
wherein the semiconductor layer further includes a first semiconductor layer containing Si and Ge as constituent elements and p-type impurities; and
a second semiconductor layer provided in a region under the first semiconductor layer, made of Si, and containing p-type impurities.
36. The semiconductor device according to claim 35, wherein the semiconductor layer further includes a Si layer containing p-type impurities and is sandwiched between the first semiconductor layer and the gate insulator film.
37. The semiconductor device according to claim 35, further comprising a conductor member for electrically connecting the gate electrode and the second semiconductor layer.
38. The semiconductor device according to claim 35; wherein at least an uppermost portion of the substrate comprises an insulator.
39. The semiconductor device according to claim 35, wherein the gate electrode comprises polysilicon or polysilicon germanium containing n-type impurities.
40. The semiconductor device according to claim 35, wherein the first semiconductor layer is made of SiGe.
41. The semiconductor device according to claim 35, wherein the first semiconductor layer further contains carbon in a concentration from 0.01% to 2%.
42. The semiconductor device according to claim 35, further comprising
another semiconductor layer provided on the substrate;
another gate insulator film provided on the other semiconductor layer;
another gate electrode provided on the other gate insulator film; and
p-type source and drain regions provided in regions on both sides of the other gate electrode of the other semiconductor layer,
wherein the other semiconductor layer further includes another first semiconductor layer containing Si and Ge as constituent elements and n-type impurities; and
another second semiconductor layer made of Si and containing n-type impurities is provided in a region under the first semiconductor layer.
43. The semiconductor device according to claim 42, wherein the other semiconductor layer further includes another Si layer sandwiched between the other first semiconductor layer and the other gate insulator film and containing n-type impurities.
44. The semiconductor device according to claim 35, wherein a concentration of the p-type impurities contained in the second semiconductor layer is higher than a concentration of the p-type impurities contained in the first semiconductor layer.
45. The semiconductor device according to claim 36, wherein a concentration of the p-type impurities contained in the first semiconductor layer is the same as a concentration of the p-type impurities contained in the Si layer.
46. The semiconductor device according to claim 36, wherein a concentration of the p-type impurities contained in the second semiconductor layer is higher than a concentration of the p-type impurities contained in the first semiconductor layer, and
a concentration of the p-type impurities contained in the first semiconductor layer is the same as a concentration of the p-type impurities contained in the Si layer.
47. The semiconductor device according to claim 35, wherein the first semiconductor layer contains p-type impurities of no less than 11017 cm3.
48. The semiconductor device according to claim 35, wherein the second semiconductor layer contains p-type impurities of no less than 11018 cm3.
49. The semiconductor device according to claim 35, wherein the first semiconductor layer contains p-type impurities of no less than 11017 cm3, and the second semiconductor layer contains p-type impurities of no less than 11018 cm3.