Complex phase difference sensing device of sample surface shape
Provided is a complex sensing device including a thickness sensing device including pulse generating device configured to generate a probe pulse and a pump pulse, a first optical splitter configured to split the probe pulse and direct the pump pulse to a surface of a sample and generate an acoustic signal in the sample, a detector configured to receive a reflection probe pulse generated by the probe pulse being reflected from the sample, a first processor configured to receive and process a first signal from the detector, and a second optical splitter on a path of the reflection probe pulse from the sample to the detector, the second optical splitter being configured to split the reflection probe pulse, and a surface shape sensing device configured to receive a split probe pulse split from the first optical splitter and a split reflection probe pulse split from the second optical splitter, and measure a surface shape of the sample based on a phase difference between the split probe pulse and the split reflection probe pulse.
1 . A complex sensing device comprising:
a thickness sensing device comprising:
a pulse generator configured to generate a probe pulse and a pump pulse;
a first optical splitter configured to:
split the probe pulse into a first probe pulse and a second probe pulse, and direct the first probe pulse to a surface of a sample and the second probe pulse to a surface shape sensing device; and
direct the pump pulse to the surface of the sample and generate an acoustic signal in the sample;
a detector configured to receive a reflection probe pulse generated by the first probe pulse being reflected from the sample;
a first processor configured to receive and process a first signal from the detector; and
a second optical splitter on a path of the reflection probe pulse reflected from the sample to the detector, the second optical splitter being configured to split the reflection probe pulse; and
the surface shape sensing device configured to receive the second probe pulse split from the first optical splitter and a split reflection probe pulse split from the second optical splitter, and measure a surface shape of the sample based on a phase difference between the second probe pulse and the split reflection probe pulse.
2 . The complex sensing device of claim 1 , wherein the pulse generator comprises:
a light source configured to generate pulses;
a pulse splitter configured to split the pulses into the probe pulse and the pump pulse; and
a delay stage configured to delay the probe pulse.
3 . The complex sensing device of claim 1 , wherein the surface shape sensing device comprises:
a radio frequency (RF) signal source configured to generate a microwave signal;
a first phase detector configured to synchronize the microwave signal with the second probe pulse;
a second phase detector configured to receive the split reflection probe pulse and the microwave signal, and output a second signal corresponding to a phase error between the microwave signal with the second probe pulse; and
a second processor configured to receive and process the second signal.
4 . The complex sensing device of claim 1 , wherein the surface shape sensing device comprises:
an electric pulse generator configured to photoelectrically convert the second probe pulse into an electric pulse;
a phase detector configured to output a second signal corresponding to a phase error of the split reflection probe pulse and the electric pulse; and
a second processor configured to receive and process the second signal.
5 . The complex sensing device of claim 3 , wherein the second processor is further configured to receive the first signal and the second signal, and correct an amount of light based on the second signal to measure the surface shape of the sample.
6 . The complex sensing device of claim 5 , wherein the second processor is further configured to correct the amount of light based on the first signal generated through the reflection probe pulse prior to being affected by the acoustic signal.
7 . The complex sensing device of claim 5 , wherein the second processor is further configured to correct the amount of light based on the first signal generated through the reflection probe pulse when being affected by the acoustic signal.
8 . The complex sensing device of claim 3 , wherein the second processor is further configured to obtain a shape of an interface inside the surface of the sample by combining a value obtained from the thickness sensing device and a value obtained from the surface shape sensing device.
9 . The complex sensing device of claim 8 , wherein the shape of the interface is obtained based on the surface shape obtained from the surface shape sensing device, excluding a thickness obtained from the thickness sensing device.
10 . The complex sensing device of claim 1 , further comprising a carrier configured to move the sample in a plane to continuously sense the sample.
11 . The complex sensing device of claim 3 , wherein the first phase detector is further configured to output the phase error between the microwave signal and the second probe pulse and provide the phase error to the RF signal source to synchronize the microwave signal with the second probe pulse.
12 . The complex sensing device of claim 1 , wherein the pulse generator has a wavelength greater than or equal to 750 nm and less than or equal to 850 nm, and a pulse repetition rate less than or equal to 100 MHz.
13 . A complex sensing device comprising:
a thickness sensing device comprising:
a pulse generator configured to generate a probe pulse and a pump pulse;
a first optical splitter configured to:
split the probe pulse into a first probe pulse and a second probe pulse, and direct the first probe pulse to a surface of a sample and the second probe pulse to a surface shape sensing device; and
direct the pump pulse to the surface of the sample and generate an acoustic signal in the sample;
a detector configured to receive a reflection probe pulse generated by the first probe pulse being reflected from the sample;
a second optical splitter on a path of the reflection probe pulse reflected from the sample to the detector, the second optical splitter being configured to split the reflection probe pulse;
a first processor configured to receive and process a first signal from the detector; and
a phase detector configured to receive a split reflection probe pulse split from the reflection probe pulse; and
the surface shape sensing device configured to obtain a surface shape of the sample based on the second probe pulse split from the probe pulse and a signal output from the phase detector for measurement.
14 . The complex sensing device of claim 13 , wherein the surface shape sensing device comprises:
a radio frequency (RF) signal source configured to output a microwave signal; and
a synchronization phase detector configured to input the microwave signal and the second probe pulse, and synchronize the microwave signal output from the RF signal source with the second probe pulse,
wherein the phase detector is further configured to output a phase error of the synchronized microwave signal and the split reflection probe pulse respectively input to the phase detector and output a second signal corresponding to the phase error.
15 . The complex sensing device of claim 13 , wherein the surface shape sensing device comprises an electric pulse generator that is configured to photoelectrically convert the second probe pulse and output an electric pulse input to the phase detector,
wherein the phase detector is further configured to output a second signal corresponding to a phase error of the electrical pulse and the split reflection probe pulse input to the phase detector.
16 . The complex sensing device of claim 14 , further comprising a processor configured to receive the first signal and the second signal, and correct an amount of light based on the second signal to measure the surface shape of the sample.
17 . The complex sensing device of claim 16 , wherein the processor is further configured to correct the amount of light based on the first signal generated based on the reflection probe pulse when the pump pulse reaches the sample or prior to the pump pulse reaches the sample.
18 . A complex sensing method comprising:
emitting a probe pulse and a pump pulse from a pulse generator;
splitting the probe pulse into a first probe pulse and a second probe pulse, and directing the first probe pulse toward a sample and the second probe pulse to a surface shape sensing device by a first optical splitter;
irradiating the sample with the pump pulse and the first probe pulse;
transmitting a reflection probe pulse, which is the first probe pulse reflected by the sample, to a detector;
splitting the reflection probe pulse toward the detector by a second optical splitter;
inputting the second probe pulse split from the probe pulse by the second optical splitter and a split reflection probe pulse split from the reflection probe pulse by the second optical splitter to the surface shape sensing device;
sensing a thickness of the sample based on a change in reflectance of the sample obtained by the detector; and
sensing a surface shape of the sample through time of flight difference data between the second probe pulse and the split reflection probe pulse in the surface shape sensing device.
19 . The method of claim 18 , wherein the sensing of the surface shape comprises sensing the surface shape of the sample by correcting the time of flight difference data through reflectance change data of the sample.