CN112017983A - Method for detecting contact hole and processing method for semiconductor product - Google Patents

Abstract

The present application discloses a method for detecting a contact hole and a method for processing a semiconductor product. The detection method is used for detecting poorly opened contact holes on a semiconductor structure; the semiconductor structure includes a wafer and an oxide layer on the wafer; the oxide layer is provided with a plurality of penetrating oxide layers. The contact hole of the layer; the detection method includes: performing an epitaxial growth process on the wafer, so as to generate a silicon single crystal in the contact hole; detecting the semiconductor structure by optical inspection equipment, The contact hole of the silicon single crystal was determined to be a poorly opened contact hole. The method for detecting a poorly opened contact hole provided by the embodiment of the present disclosure can quickly, comprehensively and accurately detect whether the semiconductor structure has a poorly opened contact hole problem by using an optical inspection device.

Description

Method for detecting contact hole and processing method for semiconductor product

technical field

The present disclosure relates to the technical field of semiconductors, and in particular, to a method for detecting poorly opened contact holes and a method for processing semiconductor products.

Background technique

In the semiconductor manufacturing process, contact holes need to be formed in order to connect wires. Semiconductor chips are shrinking, and contact holes are getting smaller and deeper, making it increasingly difficult to create perfect contact holes. If the contact holes are not well made and the wires cannot be connected to the wires, it is called poor opening of the contact holes. Although the poor opening will be inspected by electron beam inspection equipment, sometimes due to some reasons, the defective problem cannot be detected. Among the many defects that occur in the semiconductor manufacturing process, an electron beam inspection apparatus is used to inspect the problem of poor opening of the contact hole that occurs when the contact hole is etched. The low measurement speed of electron beam inspection equipment makes it impossible to measure the entire wafer. During etching, if a very thin insulating film remains on the bottom of the contact, it is impossible to detect the problem of poor opening.

When using electron beam inspection equipment to inspect the poor opening of the contact holes, as shown in Figures 1 and 2, if the insulating films 3 and 4 remain in the contact holes 6 (wherein the insulating film 3 is thinner than the insulating film 4, the insulating film may be an oxide material. made), then the electrons under the contact hole 6 cannot pass through the insulating films 3 and 4 to the outside, so the opening of the contact hole 6 on the far right shown in FIG. 2 looks dark, causing the electron beam inspection equipment to fail The contact hole opening defect is detected. As shown in FIG. 3 and FIG. 4 , the electrons generated under the contact hole 6 with a large depth are absorbed by the oxide layer 5, and the number of electrons reaching the outside is very small, and the electron beam inspection equipment cannot detect it, so it is difficult to A condition is distinguished from an open bad condition. In addition, the inspection speed of electron beam inspection equipment is quite slow, and the area and time that can be inspected are quite limited.

SUMMARY OF THE INVENTION

The purpose of the present disclosure is to provide a method for detecting a contact hole and a method for processing a semiconductor product. In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be an extensive review, nor is it intended to identify key/critical elements or delineate the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the detailed description that follows.

According to an aspect of the embodiments of the present disclosure, a method for detecting contact holes is provided, which is used for detecting poorly opened contact holes on a semiconductor structure; the semiconductor structure includes a wafer and an oxide layer on the wafer. ; The oxide layer is provided with a number of contact holes penetrating the oxide layer; the detection method includes:

performing an epitaxial growth process on the wafer to generate a silicon single crystal in the contact hole;

The semiconductor structure is inspected by an optical inspection apparatus, and the detected contact hole in which the silicon single crystal is not formed is determined as a poorly opened contact hole.

According to another aspect of the embodiments of the present disclosure, a method for processing a semiconductor product is provided, including:

A semiconductor structure is provided; the semiconductor structure includes a wafer and an oxide layer on the wafer; a plurality of contact holes penetrating the oxide layer are formed on the oxide layer;

Using the above-mentioned detection method to detect the poorly opened contact hole on the semiconductor structure;

A planarization operation is performed to remove a portion of the silicon single crystal higher than the top surface of the oxide layer.

According to another aspect of the embodiments of the present disclosure, there is provided an electronic device including a semiconductor product processed by the above-mentioned processing method.

The technical solution provided by one aspect of the embodiments of the present disclosure may include the following beneficial effects:

The contact hole detection method provided by the embodiment of the present disclosure can quickly, comprehensively and accurately detect whether there is a problem of poor opening of the contact hole in the semiconductor structure by using the optical inspection equipment.

Other features and advantages of the present disclosure will be set forth in the description that follows, and, in part, will become apparent from the description, or may be inferred or unambiguously determined from the description, or may be practiced by practice of the present disclosure. example to understand. The objectives and other advantages of the present disclosure may be realized and attained by the structure particularly pointed out in the written description, claims, and drawings.

Description of drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments described in the present disclosure. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative efforts.

Fig. 1 shows the schematic diagram of the prior art that there is an insulating film in the contact hole, which leads to poor opening of the contact hole, so that the electrons under the contact hole cannot pass through the insulating film; wherein, e represents electrons, and the arrow direction represents the movement direction of electrons;

Fig. 2 shows the top view of Fig. 1;

FIG. 3 shows a schematic diagram of a large depth contact hole in the prior art;

Fig. 4 shows the top view of Fig. 3;

FIG. 5 shows a flowchart of a method for detecting a contact hole according to an embodiment of the present disclosure;

FIG. 6 shows a schematic diagram of a semiconductor structure with contact holes opened according to an embodiment of the present disclosure;

FIG. 7 shows a schematic structural diagram of an embodiment of the present disclosure after epitaxial growth;

FIG. 8 shows a schematic structural diagram of the silicon single crystal after removing the part of the silicon single crystal higher than the top surface of the oxide layer according to an embodiment of the present disclosure;

FIG. 9 shows an image facing the opening direction of the contact hole obtained when the problem of poor opening of the contact hole is detected according to an embodiment of the present disclosure.

Detailed ways

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that these descriptions are exemplary only, and are not intended to limit the scope of the present disclosure. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.

Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. The figures are not to scale, some details have been exaggerated for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships are only exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art should Regions/layers with different shapes, sizes, relative positions can be additionally designed as desired.

In the context of this disclosure, when a layer/element is referred to as being "on" another layer/element, it can be directly on the other layer/element or intervening layers/elements may be present therebetween. element. In addition, if a layer/element is "on" another layer/element in one orientation, then when the orientation is reversed, the layer/element can be "under" the other layer/element.

The first embodiment of the present disclosure provides a contact hole detection method for detecting poorly opened contact holes on a semiconductor structure; as shown in FIGS. 5-8 , the semiconductor structure includes a wafer 1 and a The oxide layer 5 on the circle 1; the oxide layer 5 is provided with a number of contact holes 6 penetrating the oxide layer 5; the detection method includes:

S10 , performing an epitaxial growth process on the wafer 1 so as to generate a silicon single crystal 7 in the contact hole 6 .

The oxide layer 5 may be a silicon oxide layer. The epitaxial growth process can be a vapor phase epitaxy process, a liquid phase epitaxy process or a molecular beam epitaxy process. Specifically, the epitaxial growth in this step refers to depositing a single crystal layer with the same crystal orientation as the wafer 1 on the wafer 1 , as if the wafer 1 "grew" outwards for a section.

S20. The semiconductor structure is inspected by an optical inspection device, and the detected contact hole 6 in which the silicon single crystal 7 is not formed is determined as a contact hole with poor opening.

The method of this embodiment can quickly and accurately detect the poor opening of the contact hole that cannot be detected by the electron beam inspection device through the optical inspection device. The inspection speed is fast, and the area and time that can be inspected are not limited. With the method of this embodiment, it is not necessary to use electron beam inspection equipment, and optical inspection equipment is used to inspect whether there is a problem of poor opening of the contact hole, and whether the problem of poor opening of the contact hole in the semiconductor structure can be quickly, comprehensively and accurately detected. In order to quickly improve the poor opening of the contact hole and improve the yield. As shown in FIG. 9 , the image obtained by the method of this embodiment is directly opposite to the opening direction of the contact hole, and the spot 8 shows the opening of the contact hole with poor opening.

A second embodiment of the present application provides a method for processing a semiconductor product, including:

S1. Provide a semiconductor structure.

As shown in FIGS. 5-8 , the semiconductor structure includes a wafer 1 and an oxide layer 5 on the wafer 1 ; the oxide layer 5 is provided with a plurality of contact holes 6 penetrating the oxide layer 5 .

Specifically, a semiconductor structure is provided, including:

S101 , providing a wafer 1 .

S102 , depositing an oxide layer 5 on the wafer 1 .

S103 , etching a plurality of contact holes 6 through the oxide layer 5 on the oxide layer 5 .

The etching is dry etching or wet etching.

S2. Use the detection method of the first embodiment of the present application to detect the poorly opened contact hole 6 on the semiconductor structure.

S3 , performing a planarization operation on the semiconductor structure, and removing the part of the silicon single crystal 7 higher than the top surface of the oxide layer 5 .

The planarization operation may be a chemical mechanical polishing operation or a dry etching operation. The planarization operation can ensure that the top surface of the oxide layer 5 remains flat.

The chemical mechanical polishing operation includes alternately performing chemical action treatment and mechanical action treatment on the portion of the silicon single crystal 7 higher than the top surface of the oxide layer 5 (ie, the silicon single crystal higher than the top surface of the oxide layer 5) until the silicon The portion of the single crystal 7 higher than the top surface of the oxide layer 5 (the silicon single crystal higher than the top surface of the oxide layer 5 ) is completely removed.

Wherein, the chemical action treatment includes: using a polishing solution to process the part of the silicon single crystal 7 higher than the top surface of the oxide layer 5 (that is, the silicon single crystal higher than the top surface of the oxide layer 5 ), so that the part higher than the top surface of the oxide layer 5 is higher than the top surface of the oxide layer 5 . The surface part of the surface part (ie, the silicon single crystal higher than the top surface of the oxide layer 5 ) chemically reacts with the polishing liquid to form a soft layer.

The mechanical action treatment includes: removing the soft layer by rubbing, so that the remaining silicon single crystal higher than the top surface of the oxide layer 5 is exposed again.

The rubbing to remove the soft layer includes: rubbing and removing the soft layer with abrasives in the polishing pad and the polishing liquid.

The equipment required for chemical polishing operations includes polishing machines, polishing liquids, polishing pads, and the like. In the process of chemical mechanical polishing, even if the semiconductor structure rotates relative to a polishing pad under the action of a certain down pressure and polishing liquid (a mixture of ultra-fine grain abrasives, chemical oxidants and liquid media), with the help of the abrasive The removal of the portion of the silicon single crystal 7 higher than the top surface of the oxide layer 5 is accomplished by mechanical grinding and etching by chemical oxidants.

A third embodiment of the present application provides an electronic device including a semiconductor product processed by the processing method of the second embodiment. The electronic devices include smart phones, computers, tablet computers, wearable smart devices, artificial intelligence devices, and power banks.

In the above description, technical details such as patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as those described above. Additionally, although the various embodiments have been described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

Embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only, and are not intended to limit the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims (8)

1. A detection method for a contact hole, characterized in that it is used to detect a poorly opened contact hole on a semiconductor structure; the semiconductor structure comprises a wafer and an oxide layer positioned on the wafer; the oxidation A number of contact holes penetrating the oxide layer are opened on the material layer; the detection method includes: performing an epitaxial growth process on the wafer to generate a silicon single crystal in the contact hole; The semiconductor structure is inspected by an optical inspection apparatus, and the detected contact hole in which the silicon single crystal is not formed is determined as a poorly opened contact hole. 2 . The detection method according to claim 1 , wherein the epitaxial growth process adopts a vapor phase epitaxy process, a liquid phase epitaxy process or a molecular beam epitaxy process. 3 . 3. The detection method according to claim 1, wherein the oxide layer is a silicon oxide layer. 4. A method of processing a semiconductor product, comprising: A semiconductor structure is provided, the semiconductor structure includes a wafer and an oxide layer on the wafer, the oxide layer is provided with a plurality of contact holes penetrating the oxide layer; Using the detection method according to any one of claims 1 to 3 to detect a poorly opened contact hole on the semiconductor structure; A planarization operation is performed to remove a portion of the silicon single crystal higher than the top surface of the oxide layer. 5. The processing method according to claim 4, wherein the providing a semiconductor structure comprises: provide a wafer; depositing an oxide layer on the wafer; A number of contact holes penetrating through the oxide layer are etched on the oxide layer. 6 . The processing method according to claim 4 , wherein the planarizing operation is a chemical mechanical polishing operation or a dry etching operation. 7 . 7. An electronic device comprising a semiconductor product processed by the processing method of any one of claims 4 to 6. 8. The electronic device according to claim 7, comprising a smart phone, a computer, a tablet computer, a wearable smart device, an artificial intelligence device, and a power bank.

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