JPH025530A - Gettering for impurity and crystal defect - Google Patents

Abstract

PURPOSE:To prevent contamination by impurities from the surface of a semiconductor substrate and the like and to prevent element characteristics from deteriorating by a method wherein crystal defect regions are each formed in scribing lanes and the impurities from the surface of the semiconductor substrate and a crystal defect layer in the vicinity of the surface of the substrate are gettered. CONSTITUTION:Scribing lanes 3 are formed between semiconductor elements on a semiconductor substrate 1 and a crystal defect region 4 is formed in each lane 3. That is performed by a method wherein the regions 4 are formed by inflicting mechanically a damage before semiconductor element regions 2 are formed. If the crystal defect formation regions 4 are outside of the regions 2, the regions 4 may be scattered outside of the regions 2 even if the regions 4 is not as one region. Then, the elements are each formed on the regions 2 and after that, each scribing region 5 is mechanically cut. Gettering of contamination from the exterior, the interior of the substrate 1 and a crystal defect layer in the vicinity of the surface of the substrate becomes possible without performing a special heat treatment and the efficiency of the elements is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a semiconductor device, and relates to a technique for eliminating impurities and crystal defects that degrade device characteristics from a device region, that is, a gettering technique.

Conventional technology Conventional gettering technologies include ring gettering technology and intrinsic gettering technology.

Various proposals have been made, including backside damage treatment and polysilicon back seal treatment.

Problems to be Solved by the Invention In the ring-gettering technology, as shown in FIG. 3(a),
A phosphorus compound region e is formed on the back surface of the semiconductor substrate 1,
Impurities and the like are gettered during heat treatment at about 00°C, but as elements become smaller, high-temperature heat treatment has become impossible.

However, the intrinsic gettering technology is not yet effective as shown in Figure 3 (
As shown in 1)), oxygen contained in the semiconductor substrate 1 is precipitated to form an oxygen precipitate formation region 7, and an oxygen-free layer called a denoutet zone (DZ region 8) is formed on the front and back surfaces of the semiconductor substrate 1. However, during the heat treatment during element formation, the precipitated oxygen melts and the gettering ability decreases.

Techniques such as backside damage and polysilicon back sealing are available for processing the backside of semiconductor substrates, but since there is a gettering source on the backside, there is a problem in that they are less effective against contamination from the surface layer.

Means for Solving the Problems In the present invention, a crystal defect region is formed in a scribe plane region for dividing a semiconductor element formed on the surface of a semiconductor substrate into chips. The crystal defect region forming step was performed before the semiconductor element was formed or during the process of using metals. This is because after the process of using metals, high temperature treatment is not possible in the element manufacturing process, so there is no gettering effect.

It is well known that functional crystal defects themselves have the effect of gettering impurities and other defects. In the present invention, impurities from the surface of the semiconductor substrate and crystal defects near the surface can be gettered by forming a crystal defect region in the scribe plane.

Therefore, there is no need for special heat treatment of the gettering pot, and the gettering ability does not deteriorate during the process.
It is possible to prevent impurity contamination from the surface, and since it is outside the device area, the device characteristics will not deteriorate.

EXAMPLE In order to divide the semiconductor element formed on the surface of the semiconductor substrate into chips, as shown in FIG. However, in the present invention, a crystal defect region 4 is formed in the scribe plane 3 (the first
Figure (a)). In this example, before forming the semiconductor element region 2, the crystal defect region 4 was formed by mechanically damaging it. In this embodiment, the crystal defect region was formed by damaging the surface of the semiconductor substrate using a diamond cutter, but the present invention is also effective even if the crystal defect region 4 is formed by other means. Further, the crystal defect forming region does not have to be the region shown in FIG. 1(,) as long as it is outside the semiconductor element region, and may be scattered outside the semiconductor element region.

Next, after a semiconductor element was formed in region 2, the scribe region 6 was mechanically cut to obtain a semiconductor element.

The semiconductor device obtained in this example exhibited characteristics that were completely free from the effects of impurity contamination from the surface and defects generated during the device formation process.

Effects of the Invention The present invention makes it possible to remove contamination from the outside and getter the crystal defect layer inside and on the surface of a semiconductor substrate without performing any special heat treatment, thus becoming a means of improving the performance of semiconductor devices.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the present invention, FIG. 2 is a diagram for explaining a conventional element forming method, and FIG. 3 is a diagram for explaining a conventional technique. DESCRIPTION OF SYMBOLS 1...Semiconductor substrate, 2...Semiconductor element formation region, 3...Scribe plane, 4...
... Crystal defect formation region, 6 ... Scripe region, 6 ... Phosphorus compound region, 7 ... Oxygen precipitate formation region, 8 ... DZ (denutet zone) area. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1 - Hand conductor & extraction 2 - + Nose element tilt 3 - Scribe lane 4 - Missing embroidery form 4 Il power 5 - Scribe g area! - 1,000 conductor curtain branches loading/3 ~ 5 1- Salt body ts. 2・-Element form Weishuo relation 6- Synthesis investment area

Claims (2)

[Claims] (1) A method for gettering impurities and crystal defects, which comprises forming a crystal defect region in a scribe lane region formed on the surface of a semiconductor substrate before or during a semiconductor element formation process. (2) The method for gettering impurities and crystal defects according to claim 1, wherein the step of forming the crystal defect region is performed before the step of using metals in the semiconductor element forming step.