CN102181916B - Method for improving uniformity of resistivity in N type 111 crystal direction - Google Patents

Abstract

The invention relates to a method for improving the uniformity of the resistivity in an N type 111 crystal direction. The method comprises the following steps: adopting a single crystal rod in (111) crystal direction firstly to prepare seed crystal deviating to (110) direction by X angle, then introducing crystal, thus growing a single crystal body with (11X) crystal direction deviating to (110) crystal surface direction by the crystal body along the (11x) crystal direction, and then cutting the single crystal body in the (11x) crystal direction with an X angle in a deviating manner, thus cutting (111) crystal sheet. The X angle ranges from 1 degree to 5 degrees. By adopting the method, the crystal body (111) is avoided growing in a small plane, the excircle of the grown single crystal is basically round (shown in the picture 2), the atlas (shown in the picture 4) of the resistivity of the cross section of the crystal rod shows that the (111) small plane does not exist, so that the uniformity of the resistivity of the N type (111) crystal direction can be improved greatly. Simultaneously, as the outer part of the crystal body is relatively round, and the barreling yield can be improved greatly, so that the yield of crystal product can be increased.

Description

A kind of method that improves N-type 111 crystal orientation resistivity evenness

Technical field

The present invention relates to a kind of method that improves N-type 111 crystal orientation resistivity evenness, particularly resistivity evenness radially.

Background technology

After silicon crystal is cut into silicon chip, on silicon chip, to make many former devices, such as tube cores such as diode, triode, unicircuit, if the radially resistivity evenness in silicon chip is poor, the performance of many tube cores of working it out just can not consistence, radially resistivity is poorer, and the tube core consistence of making is poorer, so that device producer requires the radially resistivity of single crystal silicon material producer to be controlled at is more low better.And N-type＜111 (111) facet (as shown in fig. 1 center roundlet) effect that crystal orientation silicon crystal growth is prone to most, its crystal bar radially collection of illustrative plates of determination of resistivity (as shown in Figure 3) shows that the facet that has about 2 centimeters exists; To cause crystal orientation＜111 and occur (111) facet on the growth interface〉the crystal inhomogeneous major reason of resistivity radially.It is different that resistivity sudden change between facet district and non-facet derives from the growth mechanism in two districts.(111) facet is the atomically flat face, growth is two-dimensional nucleation lateral growth mechanism on it, the lateral growth two-forty, impurity atoms can more effectively be trapped on the growth interface, inside and outside impurity concentration is poor very large to cause facet, radially homogeneity is relatively poor to cause (111) facet, and resistivity is inhomogeneous.

Summary of the invention

The purpose of this invention is to provide a kind of method that improves N-type 111 crystal orientation resistivity evenness that prevents (111) facet effect.

The technical scheme that the present invention takes is: a kind of method that improves N-type 111 crystal orientation resistivity evenness, it is characterized in that adopting first＜111〉crystal orientation single crystal rod, prepare deflection＜110〉seed crystal of direction X angle, then carry out seeding, make crystal along＜11X〉crystal orientation, grow＜11X crystal orientation deflection＜110〉crystal plane direction single crystal, then general＜11X the single crystal in crystal orientation cuts the X angle partially, cut out＜111〉wafer get final product.

Described X angle 1～5 degree.

Adopt the inventive method, avoided the growth of crystal (111) facet, the basic rounding of monocrystalline cylindrical feature (as shown in Figure 2) of its growth, its crystal bar section resistivity collection of illustrative plates (as shown in Figure 4) shows does not have (111) faceted existence.So greatly improve N-type＜111〉the crystal orientation resistivity evenness.Simultaneously since the crystal outside than rounding, the barreling yield rate can improve greatly, therefore can improve the yield rate of crystal product.

Description of drawings

Fig. 1 is the crystal bar sectional schematic diagram before the present invention.

Fig. 2 is the crystal bar sectional schematic diagram behind the present invention.

Fig. 3 is the radially collection of illustrative plates of determination of resistivity of the front crystal of the present invention.

Fig. 4 is the crystal collection of illustrative plates of determination of resistivity radially behind the present invention.

Embodiment

The below adopts the concrete enforcement of the present invention to be described further.

One, makes crystal seed.Adopt＜111〉crystal orientation single crystal rod, cut out the seeded growth direction towards＜110 the crystal orientation departs from the seed crystals at 2 degree angles.Fleet angle wherein is generally at 1～5 degree.

Two, seeding.Adopt above-mentioned seed crystal, make crystal along＜112 the crystal orientation, grow＜112〉crystal orientation deflections＜110〉crystal plane direction single crystal.

Three, section.Utilize direction finder, partially cut 2 degree angles, cut out＜111〉wafer get final product.

Four, by above-mentioned making＜111〉wafer, according to test, radially resistivity evenness improves greatly, has also improved simultaneously the external physical characteristic of single crystal, can improve the round as a ball yield rate of monocrystalline.

Claims (1)

1. method that improves N-type 111 crystal orientation resistivity evenness, it is characterized in that adopting first＜111〉crystal orientation single crystal rod, prepare deflection＜110〉seed crystal of direction X angle, then carry out seeding, make crystal along＜11X〉crystal orientation, grow＜11X crystal orientation deflection＜110〉crystal plane direction single crystal, then general＜11X the single crystal in crystal orientation cuts 1～5 jiao partially, cut out＜111〉wafer get final product.

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