Method for selectively testing diffused sheet resistance

Abstract

The invention relates to a method for selectively testing diffused sheet resistance by using crystalline silicon. The method comprises the following steps of: firstly, selecting a crystalline silicon wafer, performing heavy doping, and setting the sheet resistance as 40-55 omega / sheet; secondly, spraying wax or other organic matters onto a grid line of a diffusion surface; thirdly, putting into back etching equipment for etching to obtain a selective emitter crystalline silicon wafer; fourthly, taking the prepared selective emitter crystalline silicon wafer out, putting into four-probe testing equipment, and gradually testing the sheet resistance corresponding to a probe moving path at different positions to obtain a data group; and lastly, analyzing the data group with Minitab software to obtain a curve diagram. Due to the adoption of the method, a monitoring silicon wafer for sheet resistance is not required, the size of a great diffusion area and a sheet resistance value can be monitored simultaneously, and reduction in the enterprise cost is facilitated.

Description

technical field [0001] The invention relates to a testing method, in particular to a method for testing selective diffusion square resistance. Background technique [0002] The current preparation of high-efficiency crystalline silicon solar cells is mainly obtained by using diffused selective emitters. It forms a heavily diffused area under the gate line to reduce the contact resistance between the electrode and crystalline silicon; it forms a light diffused area in the light receiving part (active area), which makes the short-wavelength spectral response of the battery excellent. [0003] Generally, the sheet resistance value of the crystalline silicon emitter is measured by using four probes ( figure 1 ), because the square resistance of the selective emitter active region is too large (≥75Ω / □), the preparation process is challenged, which requires real-time monitoring of the square resistance value of the active region after diffusion and timely elimination of poor diff...

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Problems solved by technology

[0007] The above methods are based on different methods of preparing selective emitters. In the final analysis, these methods require more monitoring chips, and most of the monitoring chips will be treated as reworked chips; Matching (mismatch may lead to over-burning or under-burning of the cell), and the current method does not monitor the sheet resistance of the heavy diffusion area, which affects the efficiency and yield of the cell, which is not conducive to the cost control of the enterprise

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