Probe-based data collection system with adaptive mode of probing controlled by local sample properties

Abstract

A method for testing an integrated circuit (IC) using a nanoprobe, by using a scanning electron microscope (SEM) to register the nanoprobe to an identified feature on the IC; navigating the nanoprobe to a region of interest; scanning the nanoprobe over the surface of the IC while reading data from the nanoprobe; when the data from the nanoprobe indicates that the nanoprobe traverse a feature of interest, decelerating the scanning speed of the nanoprobe and performing testing of the IC. The scanning can be done at a prescribed nanoprobe tip force, and during the step of decelerating the scanning speed, the method further includes increasing the nanoprobe tip force.

1 . An apparatus for performing sample probing, comprising:
 a stage for supporting a sample;   an actuator activating a prober to collect data from the sample;   a controller collecting data signals from the prober and sending actuating signals to the actuator, the controller preprogrammed to vary the actuating signals according to the data signals received from the prober.   
     
     
         2 . The apparatus of  claim 1 , wherein the controller is further preprogrammed to read a CAD design data corresponding to the sample, and to further control the actuating signals according to the CAD design data. 
     
     
         3 . The apparatus of  claim 1 , wherein the controller is preprogrammed to vary at least one of scanning speed, amplitude of probe oscillation, gap between the probe and sample surface and probe contact force of the actuating signals, according to the data signals. 
     
     
         4 . The apparatus of  claim 2 , wherein the controller is preprogrammed to vary at least scanning speed and probe contact force of the actuating signals, according to the data signals. 
     
     
         5 . The apparatus of  claim 1 , wherein the controller is preprogrammed to vary scanning speed and probe contact force of the actuating signals by switching between at least a first and a second scanning modes, wherein the second scanning mode comprises slower speed and higher force than the first scanning mode. 
     
     
         6 . The apparatus of  claim 5 , wherein the second scanning mode further comprises a decelerating speed to a halt. 
     
     
         7 . The apparatus of  claim 1 , wherein the controller is further preprogrammed to register the prober to an image obtained by a scanning electron microscope. 
     
     
         8 . A method of performing sample probing using a prober having a probe tip, comprising the steps of:
 scanning the probe tip over the surface of the sample using a first speed and a first tip force, while reading signals obtained from the prober;   when the signals indicate that the probe tip traverses a feature of interest, decelerating the probe tip from the first speed and increasing the tip force, and thereafter performing tests on the sample using the probe tip;   when tests completed, accelerating the probe tip to the first speed and decreasing the force to the first tip force.   
     
     
         9 . The method of  claim 8 , wherein the step of decelerating is performed to cause the probe tip to stop scanning, prior to performing tests. 
     
     
         10 . The method of  claim 8 , further comprising the steps:
 registering the probe tip to the sample outside of an area of interest (ROI); and, blindly moving the probe tip to the area of interest.   
     
     
         11 . The method of  claim 10 , wherein the step of registering the probe is performed using the first speed. 
     
     
         12 . The method of  claim 10 , wherein blindly moving is performed by moving the probe tip without contacting the sample. 
     
     
         13 . The method of  claim 10 , wherein blindly moving is performed using the first speed and first force. 
     
     
         14 . The method of  claim 8 , further comprising assessing test data quality prior to accelerating the probe tip. 
     
     
         15 . A method for testing an integrated circuit (IC) using a nanoprobe, comprising:
 using a scanning electron microscope (SEM) to register the nanoprobe to an identified feature on the IC;   navigating the nanoprobe to a region of interest;   scanning the nanoprobe over the surface of the IC while reading data from the nanoprobe;   when the data from the nanoprobe indicates that the nanoprobe traverse a feature of interest, decelerating the scanning speed of the nanoprobe and performing testing of the IC.   
     
     
         16 . The method of  claim 15 , wherein the step of decelerating the scanning speed comprises decelerating to a halt. 
     
     
         17 . The method of  claim 15 , further comprises increasing tip force of the nanoprober while decelerating the scanning speed. 
     
     
         18 . The method of  claim 17 , further comprising detecting signal to noise ratio of the data from the nanoprober and ceasing to increase the probe tip force when the signal to noise ratio reaches a preset threshold. 
     
     
         19 . The method of  claim 15 , wherein the step of navigating the nanoprobe to a region of interest comprises moving the nanoprobe with the nanoprobe hovering above the surface of the sample. 
     
     
         20 . The method of  claim 15 , wherein the step of scanning the nanoprobe comprises scanning at a prescribed nanoprobe tip force, and wherein during the step of decelerating the scanning speed, the method further comprises increasing the nanoprobe tip force.