Q1: When shooting SEM, samples that do not conduct electricity or have poor conductivity, why spray gold or carbon?
A: When observed with scanning electron microscopy, when the incident electron beam hits the sample, it will accumulate charge on the surface of the sample, forming a charging and discharging effect, affecting the observation of the image and taking pictures. Therefore, before observation, conductive treatment, spray gold or carbon spray, so that the sample surface conducts electricity.
Q2: The mapping effect of SEM under high magnification is not good, what is the reason?
A: Mapping with too high multiples, more noise, the distribution of elements on the sample is not clear, it is not suitable for resolution; generally SEM is shot at a maximum of about 30,000 times.
Q3: The sample does not contain carbon, but the result shows that the content is higher than 70%, and the deviation from the actual situation is too large, how to deal with it?
A: Energy spectroscopy is not sensitive to elements with atomic number less than 11, there is a common error in carbon, nitrogen and oxygen, in addition, carbon pollution sources are relatively wide, such as conductive adhesive, sample and hand contact, DP pump, air dust, etc.; special attention to carbon and nitrogen oxygen and other light elements are not suitable for energy spectroscopy; in addition, if you need To mapping test, in addition to the background of the sample, there will be obvious carbon and nitrogen oxygen, which may not be distinguishable from the sample, mapping needs special attention to light elements such as carbon, nitrogen and oxygen For the content is higher than the actual value, the content can be artificially reduced.