1. A signal demodulation method, comprising:
demodulating received signals using a difference between a received signal to be demodulated and a preceding signal of the received signal;
detecting an erroneous demodulation value based on backward-demodulation of the received signals; and
correcting the erroneous demodulation value,
wherein the detecting comprises:
identifying, from the received signals, a received signal of which a demodulation value obtained through forward-demodulation differs from a demodulation value obtained through backward-demodulation; and
detecting the erroneous demodulation value using a reliability level of the received signal.
2. The method of claim 1, wherein the demodulating comprises:
determining a demodulation value of the received signal to be demodulated as a first demodulation value when a differential value is less than a first threshold, the differential value corresponding to a difference between an intensity of the received signal to be demodulated and an intensity of the preceding signal;
determining the demodulation value of the received signal to be demodulated as a second demodulation value when the differential value is greater than a second threshold; and
determining the demodulation value of the received signal to be demodulated to be a demodulation value of the preceding signal when the differential value is a value between the first threshold and the second threshold.
3. A signal demodulation apparatus, comprising:
a signal demodulator configured to demodulate received signals using a difference between a received signal to be demodulated and a preceding signal of the received signal;
an erroneous demodulation value detector configured to detect an erroneous demodulation value based on a backward-demodulation of the received signals; and
an erroneous demodulation value corrector configured to correct the erroneous demodulation value,
wherein the erroneous demodulation value detector comprises:
a backward demodulator configured to backward-demodulate the received signals;
an identifier configured to identify, from the received signals, a received signal of which a demodulation value obtained through forward-demodulation differs from a demodulation value obtained through backward-demodulation; and
a detector configured to detect the erroneous demodulation value using a reliability level of the received signal.
4. The apparatus of claim 3, wherein the signal demodulator is configured to:
determine a demodulation value of the received signal to be demodulated as a first demodulation value when a differential value is less than a first threshold, the differential value corresponding to a difference between an intensity of the received signal to be demodulated and an intensity of the preceding signal,
determine the demodulation value as a second demodulation value when the differential value is greater than a second threshold, and
determine the demodulation value of the received signal to be demodulated to be a demodulation value of the preceding signal when the differential value is a value between the first threshold and the second threshold.
5. A signal demodulation apparatus, comprising:
a signal demodulator configured to demodulate received signals using a difference between a received signal to be demodulated and a preceding signal of the received signal;
an erroneous demodulation value detector configured to detect that the demodulation value is correct, based on a backward-demodulation of the received signals; and
an erroneous demodulation value corrector configured to output that the demodulated value is correct.
6. The apparatus of claim 5, wherein the signal demodulator is configured to:
determine a demodulation value of the received signal to be demodulated as a first demodulation value when a differential value is less than a first threshold, the differential value corresponding to a difference between an intensity of the received signal to be demodulated and an intensity of the preceding signal,
determine the demodulation value as a second demodulation value when the differential value is greater than a second threshold, and
determine the demodulation value of the received signal to be demodulated to be a demodulation value of the preceding signal when the differential value is a value between the first threshold and the second threshold.
7. The apparatus of claim 6, wherein the error demodulation value detector comprises:
a backward demodulator configured to backward-demodulate the received signals;
an identifier configured to identify, from the received signals, a correct signal for which a demodulation value obtained through forward-demodulation is the same as a demodulation value obtained through backward-demodulation; and
a detector configured to detect that the demodulation value is correct when the identifier identifies a correct signal.
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 process for manufacturing a semiconductor device, comprising:
a. creating an ion beam comprising ions to be implanted in said device;
b. focusing said ion beam by passing said ion beam between an upper magnetic core member and a lower magnetic core member spaced apart from said upper core member, said lower core member being oriented with its axis substantially parallel to the axis of said upper core member, wherein a plurality of focusing coil units are distributed along said upper core member and corresponding focusing coil units are distributed along said lower core member, each said focusing coil unit comprising a single continuous electrical circuit that surrounds an individual core member;
c. exciting said focusing coil units distributed along said upper core member and said corresponding focusing coil units distributed along said lower core member such that the direction of the current in each of said excited focusing coil units distributed along said upper core member is the opposite of the direction of the current in said corresponding focusing coil units distributed along said lower core member when viewed from one end of the upper and lower core members; and
d. directing said focused beam onto said device.
2. The process of claim 1, further comprising end coil units located on said upper core member between said plurality of focusing coil units and each end of said upper core member, and end coil units located on said lower core member between said plurality of corresponding focusing coil units and each end of said lower core member.
3. The process of claim 2, further comprising exciting said end coil units located on said upper core member in the opposite direction from the current in said end coil units located on said lower core member.
4. The process of claim 1, wherein the current in each of said focusing coil units distributed along said upper core member is in the same direction.
5. A process for manufacturing a semiconductor device, comprising:
a. creating an ion beam comprising ions to be implanted in said device;
b. focusing said ion beam by passing said ion beam between an upper magnetic core member, a lower magnetic core member spaced apart from said upper core member, said lower core member being oriented with its axis substantially parallel to the axis of said upper core member and its ends substantially aligned with the ends of said upper core member, and additional members connecting said ends of said magnetic core members so as to form a rectangular frame; where a plurality of independent current excited coil units are distributed along said upper core member and corresponding coil units are distributed along said lower core member, each said coil unit comprising a single continuous electrical circuit that surrounds an individual core member;
c. exciting said coil units distributed along said upper core member and said corresponding coil units distributed along said lower core member such that the direction of the current in each of said excited coil units distributed along said upper core member is the opposite of the direction of the current in said corresponding coil units distributed along said lower core member when viewed from one end of the upper and lower core members; and
d. directing said focused beam onto said device.
6. The process of claim 5, further comprising at least one coil unit distributed on each of said additional members.
7. The process of claim 6, further comprising exciting said at least one coil unit on one of said additional members in one direction and said at least one coil unit on the opposite additional member in an opposite direction.
8. A process for manufacturing a semiconductor device, comprising:
a. creating an ion beam comprising ions to be implanted in said device;
b. focusing said ion beam by passing said ion beam between an upper magnetic core member and a lower magnetic core member spaced apart from said upper core member, said lower core member being oriented with its axis substantially parallel to the axis of said upper core member, wherein a plurality of focusing coil units are distributed along said upper core member and corresponding focusing coil units are distributed along said lower core member, each said focusing coil unit comprising a single continuous electrical circuit that surrounds an individual core member;
c. exciting one of said focusing coil units distributed along said upper core member and its corresponding focusing coil unit distributed along said lower core member such that the direction of the current in said one excited focusing coil unit distributed along said upper core member is the opposite of the direction of the current in said corresponding focusing coil unit distributed along said lower core member when viewed from one end of the upper and lower core members; and
d. directing said focused beam onto said device.
9. The process of claim 8, further comprising end coil units located on said upper core member between said plurality of focusing coil units and each end of said upper core member, and end coil units located on said lower core member between said plurality of corresponding focusing coil units and each end of said lower core member.
10. The process of claim 9, further comprising exciting said end coil units located on said upper core member in the opposite direction from the current in said end coil units located on said lower core member.
11. The process of claim 8, wherein the current in each of said focusing coil units distributed along said upper core member is in the same direction.