# US 10,122,946 B2 · Method for detecting particulate radiation

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,122,946 B2
- Document ID: US10122946B2
- Status: Granted
- Kind: B2
- Application number: 15/218,465
- Filed: 2016-07-25
- Published: 2017-05-11
- Granted: 2018-11-06
- Earliest claimed: 2015-11-11
- Assignees: FEI Company
- Applicants: FEI Company
- Inventors: Bart Jozef Janssen; Erik Michiel Franken; Maarten Kuijper; Lingbo Yu
- Web page: https://patentgrep.com/patent/US10122946B2

## CPC

- H04N 25/48: Increasing resolution by shifting the sensor relative to the scene
- G01T 1/247: {Detector read-out circuitry (for processing gain or off-set correction H04N)}
- G06T 3/4069: by subpixel displacements
- H04N 25/10: for transforming different wavelengths into image signals
- H10F 39/1892: {Direct radiation image sensors}
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00)
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION

## Abstract

When detecting particulate radiation, such as electrons, with a pixelated detector, a cloud of electron/hole pairs is formed in the detector. Using the signal caused by this cloud of electron/hole pairs, a position of the impact is estimated. When the size of the cloud is comparable to the pixel size, or much smaller, the estimated position shows a strong bias to the center of the pixel and the corners, as well to the middle of the borders. This hinders forming an image with super-resolution. By shifting the position or by attributing the electron to several sub-pixels this bias can be countered, resulting in a more truthful representation.

## Claims

### Claim 1

A method of detecting particulate radiation using a semiconductor based pixelated detector, the detector pixels having a detector pixel size, the detector sensitive to the particulate radiation, each particle of the particulate radiation causing a multitude of electron/hole pairs in the semiconductor material of the detector, the multitude of electron/hole pairs having a centroid and a centroid extent, the extent of the centroid extent larger than the detector pixel size, the method comprising:
intercepting a particle of the particulate radiation,
estimating the number of electron/hole pairs for a number of adjacent detector pixels,
estimating the position of the centroid of the number of electron/hole pairs using the estimates of electron/hole pairs in adjacent detector pixels,
estimating the impact position of the particle using said estimated position of the centroid, said estimated impact position having a position dependent bias depending on the position within the detector pixel,
forming a pixelated image using the estimated position of a multitude of estimated impact positions, the pixelated image consisting of image pixels having an intensity, and
adjusting the contribution of each estimated impact position to corresponding image pixels to counter the effect of said position dependent bias within the adjacent detector pixels.

### Claim 2 (depends on 1)

The method of claim 1 in which the adjustment of the contribution of each estimated impact position to corresponding image pixels comprises the adjustment of the estimated position, the adjustment a function of the estimated impact position relative to the detector pixel.

### Claim 3 (depends on 1)

The method of claim 1 in which the adjustment of the contribution of each estimated impact position to corresponding image pixels comprises adding intensity to more than one image pixel.

### Claim 4 (depends on 2)

The method of claim 2 in which the function is a function from the group of spline functions.

### Claim 5 (depends on 2)

The method of claim 2 in which the function is stored in a look-up table (LUT).

### Claim 6 (depends on 1)

The method of claim 1, in which the particulate radiation is particulate radiation from the group of electrons, ions, and X-rays.

### Claim 7 (depends on 2)

The method of claim 2, in which the adjustment of the contribution of each estimated impact position to corresponding image pixels comprises adding intensity to more than one image pixel.

### Claim 8 (depends on 3)

The method of claim 3, in which the function is a function from the group of spline functions.

### Claim 9 (depends on 3)

The method of claim 3, in which the function is stored in a look-up table (LUT).

### Claim 10 (depends on 2)

The method of claim 2, in which the particulate radiation is particulate radiation from the group of electrons, ions, and X-rays.

### Claim 11 (depends on 3)

The method of claim 3, in which the particulate radiation is particulate radiation from the group of electrons, ions, and X-rays.

### Claim 12 (depends on 4)

The method of claim 4, in which the particulate radiation is particulate radiation from the group of electrons, ions, and X-rays.

### Claim 13 (depends on 5)

The method of claim 5, in which the particulate radiation is particulate radiation from the group of electrons, ions, and X-rays.