X-ray photoelectron emission spectrometry system

An x-ray photoelectron emission analyzer apparatus for analyzing a sample in an evacuated chamber, the apparatus comprising:

• an x-ray source;
• collimating means for collimating x-rays from the source for providing a collimated x-ray beam which interacts with the sample within the evacuated chamber, wherein the sample includes an optically polished top layer;
• grazing incidence angle adjustment means for adjusting the collimated x-ray beam for permitting the collimated x-ray beam to interact with the sample with an adjustable grazing incidence angle;
• electron detector means, maintained in a predetermined, fixed orientation with respect to the sample, for detecting photoelectron emission from the sample, wherein said electron detector means includes an electron energy analyzer and means for providing a record of the quantity and kinetic energies of electrons photoemitted from the sample;
• fixed sample support means for maintaining the sample in the evacuated chamber in a predetermined, fixed orientation with respect to said electron detector means;
• and
• means for monitoring the grazing incidence angle of the collimated x-ray beam that interacts with the sample, wherein said grazing incidence angle monitoring means includes means for detecting x-rays reflected off of the sample.

A method for analyzing a multilayer sample having a first layer and a second layer, wherein the first layer is a top layer and has a first-layer critical angle, and wherein the second layer has a second-layer critical angle, the method comprising the steps of:

• supporting the sample in a evacuated chamber with a predetermined, fixed orientation with respect to an electron detector;
• directing a collimated x-ray beam to the sample at a grazing incidence angle with respect to the sample;
• monitoring a grazing exit angle of the collimated x-ray beam with respect to the sample by detecting x-rays reflected off of the sample with an x-ray detector and generating data representing the grazing angle;
• controlling the incidence angle with respect to the sample such that the incidence angle is set to one or more incidence angles between the first-layer critical angle and the second layer critical angle;
• detecting photoelectron emission from the sample with the electron detector and generating data representing an energy distribution of the detected photoelectron emission for the one or more incidence angles;
• evaluating the data, for the one or more incidence angles, representing the energy distribution of the detected photoelectron emission to determine peaks in intensity of photoemission at specific energies corresponding to different chemical species and
• determining thickness of the first layer based on the intensity of photoelectron emission peaks corresponding to the chemical species of the first and second layers at the one or more incidence angles.

A method for analyzing a multilayer sample having a first layer and a second layer, wherein the first layer is a top layer and has a first-layer critical angle, and wherein the second layer has a second-layer critical angle, the method comprising the steps of:

• supporting the sample in a evacuated chamber with a predetermined, fixed orientation with respect to an electron detector, wherein the sample is a semiconductor and has an optically polished first layer;
• directing a collimated x-ray beam to the sample at a grazing incidence angle with respect to the sample;
• monitoring the grazing incidence angle of the collimated x-ray beam with respect to the sample by detecting x-rays reflected off of the sample with an x-ray detector and generating data representing the grazing incidence angle;
• controlling the grazing incidence angle with respect to the sample such that the incidence angle includes angles greater than the first-layer critical angle and less than the second layer critical angle;
• detecting photoelectron emission from the sample with the electron detector and generating data representing the quantity of electrons at each kinetic energy;
• evaluating the data representing the energy distribution of the detected photoelectron emission to determine peaks in intensity corresponding to photoemission from different chemical species;
• and
• determining thickness of the first layer based on comparing the intensity of peaks due to photoemission from the different chemical species at different incidence angles.

A method for analyzing a sample, comprising the steps of:

• supporting the sample in a evacuated chamber with a predetermined, fixed orientation with respect to an electron detector;
• directing a collimated x-ray beam at a grazing incidence angle with respect to the sample;
• monitoring a grazing exit angle of the collimated x-ray beam with respect to the sample by detecting x-rays reflected off of the sample with an x-ray detector:
• controlling the grazing incidence angle of the collimated x-ray beam with respect to the sample based on the monitored grazing exit angle of the x-rays reflected off of the sample;
• detecting photoelectron emission from the sample with the electron detector;
• and
• evaluating the detected photoelectron emission to determine different chemical species in the sample.