GB/T 26068-2018Test method for carrier recombination lifetime in silicon wafers and silicon ingots—Non-contact measurement of photoconductivity decay by microwave reflectance method (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 26068-2010 "Test method for contactless microwave reflection photoconductivity attenuation of silicon wafer carrier lifetime".

Compared with GB/T 26068-2010, this standard is subject to the following editorial changes.

--- Change the standard name "Silicon carrier carrier lifetime lifetime non-contact microwave reflection photoconductivity attenuation test method" to "silicon wafer and silicon ingot Test of carrier recombination lifetime non-contact microwave reflection photoconductivity attenuation method;

--- Increased the use of microwave reflection photoconductivity attenuation method to test the composite lifetime of single crystal silicon ingots and cast polycrystalline silicon wafers, silicon ingot carriers Rong (see Chapter 1, 9.2);

--- Change the lower limit of the room temperature resistivity of the test sample in the range from "0.05 ohm · cm ~ 1 ohm · cm" to "0.05 ohm · cm ~ 10 ohm · Cm", the test range of carrier recombination life is changed from "0.25µs to >1ms" to " >0.1µs", and the 2010 version is deleted. 1.3 (see Chapter 1, 1.2, 1.3 of the 2010 edition);

--- Added GB/T 1551 to the normative reference file, deleted GB/T 1552, SEMIMF1388, SEMIMF1530, deleted In addition to the age number in GB/T 1553-2009 and YS/T 679-2008, the number of GB/T 11446.1 was added to 2013. (See Chapter 2, Chapter 2 of the 2010 edition);

--- Revised the definition of terminology injection level, composite life, surface recombination rate, body recombination life and 1/e life (see Chapter 3, Chapter 3 of the 2010 edition);

--- Adjust some parts of the 2010 edition 1/e life definition to the interference factor 5.16, and the 1/e life definition is adjusted to the interference factor 5.13 (see 5.10, 5.17, 3.6 of the 2010 edition);

--- Increased the "carrier diffusion length is less than 0.1 times the thickness of the silicon wafer, you can consider not processing the sample surface, direct detection", The surface treatment method adds "surface continuous corona charging" (see 5.1);

--- Increased recommended test temperature and humidity, small signal conditions, carrier trap or depletion zone, test point distance edge distance test The impact of the test results (see 5.5, 5.6, 5.9, 5.18, 5.20);

--- Adjust the 7.1 part of the 2010 edition to 5.19 (see 5.19, 7.1 of the 2010 edition);

--- Added "the use of wavelength segments of thin films, thin layers, thin silicon wafers or other materials is subject to testing by relevant departments or organizations" (see 6.2);

--- Added "If the thickness of the silicon wafer is less than 150µm, it is advisable to use a non-metallic wafer holder" (see 6.5);

--- Modify the water requirements to "meet the requirements of EW-III or better in GB/T 11446.1-2013 (see 7.1, 2010 edition) 7.2);

--- Clear the purity level of iodine, absolute ethanol, hydrofluoric acid, nitric acid (see 7.2, 7.3, 7.4, 7.5);

--- Removed the content of the sampling (see 8.1 of the 2010 edition);

---Sample preparation adds "the need to remove residuals from the surface of the sample by mechanical and chemical mechanical polishing or by chemical polishing only After injury" (see 8.2);

--- Defined the specific operation mode of silicon wafer oxidation treatment [see 8.2a), 2010 edition 8.4.1];

--- Surface preparation method for "continuous corona charging of silicon wafer surface" added to sample preparation [see 8.2c)];

--- Removed the corrosion time of the surface oxide of the sample with hydrofluoric acid before passivation (see.2010 edition) 8.4.2.1);

---In the silicon test step, add "If you need to record and use the status of the front and back in 9.1.1" and "Use the appropriate wavelength, Record the laser wavelength and pulse spot size used (see 9.1.3, 9.1.5);

--- Revised precision according to the test conditions (see Chapter 10, Chapter 11 of the 2010 edition);

--- Added informative Annex E and adjusted the 2010 version of Section 8.3 to Appendix E, E.3 (see Appendix E, 2010 edition 8.3).

This standard is supported by the National Semiconductor Equipment and Materials Standardization Technical Committee (SAC/TC203) and National Semiconductor Equipment and Materials Standards. The Technical Subcommittee Materials Branch (SAC/TC203/SC2) jointly proposed and managed.

1 Scope

This standard specifies the non-contact microwave reflection photoconductivity decay test for the carrier lifetime of single crystal and cast polycrystalline silicon wafers and silicon ingots. method.

This standard applies to silicon ingots and polished n-type or p-type silicon wafers (when silicon wafer thickness is greater than 1mm, commonly referred to as silicon blocks) Test of carrier recombination lifetime. This standard can also be used for test cutting or research under the condition that the conductivity detection system has sufficient sensitivity. Carrier recombination lifetime of ground and corroded silicon wafers. Generally, the lower limit of the room temperature resistivity of the sample to be tested is 0.05 ohm·cm to 10 ohm·cm. Between, is determined by the limit of the sensitivity of the detection system. The test range of carrier recombination lifetime is greater than 0.1µs, and the shortest lifetime value that can be measured depends on The shutdown characteristic of the light source and the sampling frequency of the attenuation signal detector, the longest measurable value depends on the geometry of the sample and the passivation of the surface degree.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 1550 Test method for conductivity type of extrinsic semiconductor materials

GB/T 1551 silicon single crystal resistivity determination method

GB/T 1553 Determination of minority carrier lifetime in silicon and germanium

GB/T 6616 Semiconductor silicon wafer resistivity and silicon film sheet resistance test method Non-contact eddy current method

GB/T 6618 silicon wafer thickness and total thickness variation test method

GB/T 11446.1-2013 electronic grade water

GB/T 13389 boron-doped phosphorus-doped arsenic-doped silicon single crystal resistivity and dopant concentration conversion procedure

GB/T 14264 semiconductor material terminology

YS/T 679 Steady-state surface photovoltage test method for minority carrier diffusion length in extrinsic semiconductors

SEMIMF978 Semiconductor Deep Level Transient Capacitance Test Method (Testmethodforcharacterizingsemiconductor Deeplevelsbytransientcapacitancetechniques)

3 Terms and definitions

The following terms and definitions as defined in GB/T 14264 apply to this document.