# US 2020/0400577 A1 · Method for photoluminescence measurement of a sample > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0400577 A1 - Document ID: US20200400577A1 - Status: Published application - Kind: A1 - Application number: 16/764,985 - Filed: 2018-11-20 - Published: 2020-12-24 - Earliest claimed: 2017-11-21 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Inventors: Renaud VARACHE - Web page: https://patentgrep.com/patent/US20200400577A1 ## CPC - G01N 21/6489: {Photoluminescence of semiconductors} - G01N 21/6456: {Spatial resolved fluorescence measurements; Imaging} - G01N 21/9501: {Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G01N 21/9503: {Wafer edge inspection} - H02S 50/15: using optical means, e.g. using electroluminescence - G01N 2021/646: {Detecting fluorescent inhomogeneities at a position, e.g. for detecting defects} - G01N 2021/8461: {Investigating impurities in semiconductor, e.g. Silicon} - Y02E 10/50: Photovoltaic [PV] energy - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H02S: GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES (obtaining electrical energy from radioactive sources G21H1/12; light sensitive inorganic semiconductor devices H10F; light sensitive organic semiconductor devices H10K30/00; thermoelectric devices H10N10/00; pyroelectric devices H10N15/00) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A method for photoluminescence measurement of a sample that includes a front face and a rear face linked by a contour, the sample resting, via the rear face of same, on a receiving face of an active base. The sample also includes a first region partially delimited by the contour and that emits a photoluminescence signal of an intensity, referred to as the first intensity, that is lower at any point to the average intensity of the photoluminescence signal of the sample referred to as the reference intensity, the active base emitting a photoluminescence signal of an intensity, referred to as the secondary intensity, that is at least equal to the reference intensity. The active base includes an edge that is set apart from the contour by an overlap distance and that delimits, with said contour, a peripheral section of the active base. ## Claims ### Claim 1 A method for photoluminescence measurement of a sample which comprises a front face and a rear face, connected by a contour, the sample bearing on an accommodating face of an active base plate at the rear face, the sample comprises at least one first region partly delimited by the contour and which emits a photoluminescence signal with a first intensity, at any point lower than a mean intensity of the photoluminescence signal of the sample called a reference intensity, the active base plate emitting a photoluminescence signal with a second intensity at least equal to the reference intensity, the active base plate further comprises an edge at a distance, according to a projection distance, from the contour, and delimiting a peripheral section of the active base plate with said contour. ### Claim 2 (depends on 1) The method according to claim 1, wherein the projection distance, at least at the at least one first region, is adjusted such that a variation in the intensity of the photoluminescence signal between the peripheral section and the first region, reveals a singularity locating the contour of the sample at the first region. ### Claim 3 (depends on 2) The method according to claim 2, wherein the singularity is a minimum of the photoluminescence signal intensity. ### Claim 4 (depends on 1) The method according to claim 1, wherein the first region comprises a defect density higher than a mean defect density of the sample. ### Claim 5 (depends on 1) The method according to claim 1, wherein a corona type charge is created on a second face of the active base plate opposite to the accommodating face, the corona type charge being intended to adjust the secondary intensity level. ### Claim 6 (depends on 5) The method according to claim 5, wherein the corona type charge is created by an anode and a cathode disposed facing the accommodating face and the second face respectively. ### Claim 7 (depends on 6) The method according to claim 6, wherein the anode comprises a grid interposed between the sample and the active base plate. ### Claim 8 (depends on 1) The method according to claim 1, wherein the active base plate comprises a first passivation layer covering the accommodating face, the first passivation layer being intended to heal defects likely to be present on the accommodating face. ### Claim 9 (depends on 8) The method according to claim 8, wherein the first passivation layer comprises a layer made of a dielectric material or of hydrogenated amorphous silicon. ### Claim 10 (depends on 1) The method according to claim 1, wherein the active base plate comprises a semiconductor material. ### Claim 11 (depends on 1) The method according to claim 1, wherein the sample also comprises at least one second region, partly delimited by the contour and which emits a photoluminescence signal with a second intensity equal to the reference intensity on average, the measurement method implementing masking means intended to mask the photoluminescence signal emitted by a region of the peripheral section adjoining the second region. ### Claim 12 (depends on 11) The method according to claim 11, wherein the masking means comprises an intermediate base plate interposed between the sample and the active base plate, the intermediate base plate comprising a masking region covering a region of the peripheral section adjoining the second region. ### Claim 13 (depends on 1) The method according to claim 1, wherein the at least one first region extends over the entire circumference of the sample. ### Claim 14 (depends on 1) The method according to claim 1, wherein the sample is a photovoltaic cell. ### Claim 15 (depends on 1) The method according to claim 1, wherein carrying out the process comprises exciting the sample and the peripheral section of the active base plate by a laser. ### Claim 16 (depends on 15) The method according to claim 15, wherein the laser sweeps the front face and the accommodating face at the peripheral section. ### Claim 17 (depends on 15) The method according to claim 15, wherein the laser has a size adapted to excite the sample and the active base plate simultaneously. ### Claim 18 (depends on 1) The method according to claim 1, wherein the photoluminescence signal emitted by the sample and by the active base plate is collected by a detector. ### Claim 19 (depends on 9) The method according to claim 9, wherein the dielectric material comprises at least one of the following elements chosen among: silicon dioxide, silicon nitride, and alumina. ### Claim 20 (depends on 10) The method according to claim 10, wherein the semiconductor material comprises silicon.