JPH0142137B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface finishing method for polishing the surface of a semiconductor compound for a Hall element without strain while maintaining a perfect crystal structure. Electromagnetic conversion elements using the Hall effect are commonly used as devices for electronic devices, but as various electronic devices become smaller and more sophisticated,
There is a strong demand for improved performance of the Hall element itself. For example, chemical polishing is used for the final finishing of single crystal wafers for InSb, which has the highest electron mobility among semiconductor compounds for Hall elements, but the finishing accuracy is poor and perfect crystallinity of the finished surface cannot be achieved. It was hot. In other words, in conventional chemical polishing, it is difficult to obtain a flat and smooth surface because the chemical reaction rate is different due to the influence of residual machining strain from the pre-processing process. The surface accuracy becomes even worse. The present invention improves the regularity and completeness of the surface crystal structure in the surface finish of such semiconductor materials. The present invention is a finishing method that includes polishing an intermetallic compound semiconductor material with an aqueous solution containing 0.5 to 20 wt% of an alkali halide in pure water. To explain in detail, this method takes into consideration the crystal structure characteristics of semiconductor materials and uses a polishing reaction material having a similar structure to finish the surface of the material into a perfect crystal structure without distortion. In other words, for a B3 type ionic crystal such as InSb or GaAs, an alkali halide, which is an ionic crystal whose atomic system is mainly bound by Coulomb attraction between ions with different polarities, is used, and it is placed in pure water. This is an aqueous solution containing ion, which allows distortion-free polishing to be performed by ionic reaction. For convenience, this inventive method will hereinafter be referred to as ion polishing. Here, NaBr,
There are KBr, NaCl, KCl, LiF, CaF ₂ , etc., and it is desirable that the aqueous solution in pure water contains 0.5 to 20 wt% of alkali halide in consideration of the amount of reactive dissolution. Next, as for the polishing method, after applying a rough lap using ordinary SiC or diamond abrasive grains, this ion polishing is performed. The polishing device may have any configuration as long as it can polish with an aqueous solution containing alkali halide in pure water. The holding member may be a device configured to rotate opposing wraps within the container containing the aqueous solution. In addition, in ion polishing, processing time,
It is obvious that the material of the wrap, the number of revolutions in the above-mentioned apparatus, the selection of the aqueous solution, etc. should be appropriately selected in consideration of the type and size of the material to be processed, processing accuracy, processing efficiency, etc. By the ion polishing described in detail above, the surface of the semiconductor material can be finished into a nearly perfect crystal structure. Next, an example according to the present invention will be shown to clarify its effects. A lapping device having the same configuration as that described above is used, and an InSb wafer sliced into 25 mm x 2 mm thick is adhered to the lapping plate, and the (111) side of the InSb wafer is first roughly lapped using diamond abrasive grains. After this, ion polishing was performed under the following conditions (Example A). Cloth...Polytex Supreme aqueous solution...Pure water 3, KCl powder 150g Wrap rotation speed...50rpm Processing time...30 minutes In addition, the case where the above materials were polished with diamond abrasive grains (Comparative Example B) was also carried out. Ta. The surface roughness and crystal structure regularity of InSb wafers subjected to the above two types of processing were measured. The surface roughness was measured using Talystep at a vertical magnification of 500,000 times. Crystal regularity was determined by irradiating the surface with a beam of 380keVHe ⁺ ions and measuring the backscattered light intensity. The results are shown in Figure 1.
Intensity ratio (χmin) to spectrum (R・S)
are shown in Table 1 along with the surface roughness. As is clear from the results, it can be seen that the surface finish precision and crystal regularity of the oil polish according to the present invention are significantly improved compared to the conventional method. 【table】

[Brief explanation of drawings]

Figure 1 shows channel numbers in the example.
It is a chart showing the relationship between (Channel No.) and scattered light intensity.

Claims (1)

[Claims] 1 A semiconductor compound material with an ionic crystal structure,
A surface finishing method for intermetallic compound semiconductor materials in which NaBr, KBr, NaCl, KCl, LiF, CaF ₂ , etc. are polished with an aqueous solution containing 0.5 to 20 wt% of alkali halide in pure water.