1. Method for knotting an end of a thread to a flat object containing two spaced holes for the knot comprising:
pulling the thread located in front of the holes on one side of the object through the holes to the other side of the object to form first and second loops
subsequently rotating the first loop formed by the thread that passes through by at least 270\xb0 and pulling a portion of the second loop adjacent to the first loop through the twisted first loop including an end of the thread while loosening the loop holding the end of the thread, and subsequently the knot formed is tightened.
2. Method according to claim 1, wherein the first loop is rotated by 450\xb0.
3. Method according to claim 1 wherein the end of the thread is pulled out of a hole to the other side of the object subsequent to forming the two loops.
4. Device for knotting the end of a thread to a flat object containing two spaced holes for the knot comprising:
two bars that are movable back and forth at a right angle to a surface of the object through the holes are provided, which both comprise a hook-like recess for grasping the thread, wherein one of the bars grasping an end of the thread can be moved between a front end position grasping the thread on one side of the object and a rear end position lying on the other side loosely holding the thread in the recess,
wherein the other bar is equipped at an end with an opening in front of the recess for a gripper mobile transversely in relation to the bars, whereby this other bar is movable between a front end position on one side of the object grasping the thread with a recess and a second position located on the other side of the object enabling passage of the gripper, and can be rotated in the second position by at least 270\xb0.
5. Device according to claim 4, wherein the other bar can be moved into a rear end position that is retracted from a travel range of the gripper.
6. Device according to claim 4, wherein the other bar can be rotated by 450\xb0.
7. Device according to claim 4, wherein the opening of the rotating other bar is designed as a slot joining into an end face.
8. Device according to claim 7, on end faces of fork arms forming the slot, carrier noses are provided for the thread running in a loop.
9. Device according to claim 8, wherein the carrier noses are formed by projections, which each run between an end face located at roughly a right angle to the other bar’s longitudinal axis and an inclined surface formed on a portion of the same.
10. Device according to claim 9, wherein the inclined surfaces are formed diagonally offset on the end faces.
11. Device according to claims 7, wherein or the slot is arranged at a right angle to the recess.
12. Device according to at least one of the claims, wherein the gripper comprises a clamping jaw and a locking jaw performing an opening or closing motion.
13. Device according to claim 12, wherein the gripper comprises of a flat bar with the clamping jaw formed on an end and a slide movable relative to the flat bar an end face of which interacts with the clamping jaw as the locking jaw.
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. For a gallium nitride semiconductor substrate having a 0001 gallium face terminated with gallium atoms, a method of dry-etching the gallium face, comprising:
(a) deploying the gallium nitride semiconductor substrate in a reactive-ion etching chamber to dispose the gallium face for being dry etched in the chamber;
(b) introducing a chlorine gas into the chamber; and
(c) applying an antenna power and a bias power to the substrate, the antenna power and the bias power operative to form a chlorine plasma and thereby dry etch the gallium face.
2. The gallium nitride substrate dry-etching method of claim 1, wherein the chlorine gas is introduced into the chamber at a flow rate in the range from 5 to 100 sccm, and to a pressure in the range from 0.1 to 10 Pa.
3. The gallium nitride substrate dry-etching method of claim 1, wherein:
the antenna power is in the range from 100 to 500 W; and
the bias power is in the range from 5 to 20 W.
4. The gallium nitride substrate dry-etching method of claim 1, achieving an etching depth of at least 5 \u03bcm.
5. For a gallium nitride semiconductor substrate having a 0001 gallium face terminated with gallium atoms, a method of dry-etching the gallium face, comprising:
(a) mechanically abrading the gallium face of the gallium nitride semiconductor substrate to produce a damage layer;
(b) deploying the gallium nitride semiconductor substrate in a reactive-ion etching chamber to dispose damage layer for being dry etched in the chamber;
(c) introducing a chlorine gas into the chamber; and
(d) applying an antenna power and a bias power to the substrate, the antenna power and the bias power operative to form a chlorine plasma and thereby dry etch the damage layer.
6. The gallium nitride substrate dry-etching method of claim 5, wherein the chlorine gas is introduced into the chamber at a flow rate in the range from 5 to 100 sccm, and to a pressure in the range from 0.1 to 10 Pa.
7. The gallium nitride substrate dry-etching method of claim 5, wherein:
the antenna power is in the range from 100 to 500 W; and
the bias power is in the range from 5 to 20 W.
8. The gallium nitride substrate dry-etching method of claim 5, achieving an etching depth of at least 5 \u03bcm.