Method of identifying crystal defect region in monocrystalline silicon using metal contamination and heat treatment

Abstract

The invention relates to a method of identifying crystal defect regions of monocrystalline silicon using metal contamination and heat treatment. In the method, a sample in the shape of a silicon wafer or a slice of monocrystalline silicon ingot is prepared. At least one side of the sample is contaminated with metal at a contamination concentration of about 1x10<14>to 5x10<16>atoms / cm<2>. The contaminated sample is heat-treated. The contaminated side or the opposite side of the heat-treated sample is observed to identify a crystal defect region. The crystal defect region can be analyzed accurately, easily and quickly without the use of an additional check device, without depending on the concentration of oxygen in the monocrystalline silicon.

Description

technical field

[0001] The present invention relates to a method of manufacturing wafers for use in semiconductor devices, and more particularly to a method of identifying and evaluating various defect regions present in monocrystalline silicon ingots or silicon wafers. Background technique

[0002] Generally, silicon wafers are fabricated using a floating zone (FT) or Czochralski (CZ) method. The CZ method is most widely used in the manufacture of silicon wafers. In the CZ method, polysilicon is placed in a quartz crucible. The polysilicon is heated and melted by a graphite exothermic material, and a seed crystal is immersed in the molten silicon. A single crystal silicon ingot is grown by pulling the seed upwardly while rotating the submerged seed. The grown silicon ingot is cut, etched and polished into silicon wafers.

[0003] Single crystal silicon ingots or silicon wafers may have crystal defects, such as crystal originated particles (Crystal Originated Particle, C...

Examples

Embodiment 1

[0063] figure 1 is a flowchart illustrating a method of identifying a crystal defect region according to an exemplary embodiment. figure 2 is to illustrate that according to the exemplary embodiment figure 1 Diagram of the thermal cycle in the identification method.

[0064] The present invention prepares samples in the shape of slices of silicon wafers or monocrystalline silicon ingots; contaminates at least one instance of the sample with metal; heat treats the contaminated sample; and visually inspects the contaminated or opposite side of the heat-treated sample under a spotlight to identify crystals defect area. The haze region is interpreted as a Pi region, where interstitial point defects are prevalent but cluster defects are absent; and the non-haze region is interpreted as a Pv region, where vacancy-type points are prevalent defects without cluster defects. For example, a haze pattern can be used to identify crystal defect regions, wherein the haze pattern is gene...

Embodiment 2

[0108] Figure 8 is a flowchart illustrating a method of identifying crystal defect regions according to another exemplary embodiment.

[0109] The present invention can identify all crystal defect regions of single crystal silicon without the need for another analytical method. That is to say, the present invention can simultaneously evaluate all crystal defect regions of single-crystal silicon, such as: Pv regions where vacancy-type defects are common; fine-plate-type precipitates exist; The P-band region where OiSF is generated; the Pi region where interstitial defects are prevalent; the B-band region where oxygen precipitation is generated at high concentrations by seeding heat treatment using interstitial silicon clusters; and the vacancy-rich region where interstitial silicon is prevalent (i -rich region).

[0110] In addition, the present invention can be used for any type of sample with a thickness of about 0.4 to 3 mm. That is, the present invention is applicable t...

technical field

[0001] The present invention relates to a method of manufacturing wafers for use in semiconductor devices, and more particularly to a method of identifying and evaluating various defect regions present in monocrystalline silicon ingots or silicon wafers. Background technique

[0002] Generally, silicon wafers are fabricated using a floating zone (FT) or Czochralski (CZ) method. The CZ method is most widely used in the manufacture of silicon wafers. In the CZ method, polysilicon is placed in a quartz crucible. The polysilicon is heated and melted by a graphite exothermic material, and a seed crystal is immersed in the molten silicon. A single crystal silicon ingot is grown by pulling the seed upwardly while rotating the submerged seed. The grown silicon ingot is cut, etched and polished into silicon wafers.

[0003] Single crystal silicon ingots or silicon wafers may have crystal defects, such as crystal originated particles (Crystal Originated Particle, C...

Examples

Embodiment 1

[0063] figure 1 is a flowchart illustrating a method of identifying a crystal defect region according to an exemplary embodiment. figure 2 is to illustrate that according to the exemplary embodiment figure 1 Diagram of the thermal cycle in the identification method.

[0064] The present invention prepares samples in the shape of slices of silicon wafers or monocrystalline silicon ingots; contaminates at least one instance of the sample with metal; heat treats the contaminated sample; and visually inspects the contaminated or opposite side of the heat-treated sample under a spotlight to identify crystals defect area. The haze region is interpreted as a Pi region, where interstitial point defects are prevalent but cluster defects are absent; and the non-haze region is interpreted as a Pv region, where vacancy-type points are prevalent defects without cluster defects. For example, a haze pattern can be used to identify crystal defect regions, wherein the haze pattern is gene...

Embodiment 2

[0108] Figure 8 is a flowchart illustrating a method of identifying crystal defect regions according to another exemplary embodiment.

[0109] The present invention can identify all crystal defect regions of single crystal silicon without the need for another analytical method. That is to say, the present invention can simultaneously evaluate all crystal defect regions of single-crystal silicon, such as: Pv regions where vacancy-type defects are common; fine-plate-type precipitates exist; The P-band region where OiSF is generated; the Pi region where interstitial defects are prevalent; the B-band region where oxygen precipitation is generated at high concentrations by seeding heat treatment using interstitial silicon clusters; and the vacancy-rich region where interstitial silicon is prevalent (i -rich region).

[0110] In addition, the present invention can be used for any type of sample with a thickness of about 0.4 to 3 mm. That is, the present invention is applicable t...

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