JPH1050689A - Apparatus and method for removing particles in semiconductor production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect semiconductor elements outside and inside of a clean room by the semiconductor surface of the element being fabricated with a self- composed protective seal. SOLUTION: A semiconductor element 10 includes a Si substrate 12. An upper face 12 having an SiO2 layer 14 is formed on the upper part of the element 10. A bond layer 20 is deposited on the upper face 16 and has a self- composed protective seal 30 deposited thereto, so that the radicals composed of hydroxy (OH) group at the head part form Si-O bonds during self composition. The seal 30 can be removed it any time by such a standard manufacturing procedure for gasifying this film by ultraviolet rays or standard O-plasma. Thus it is possible to protect the element 10 outside and inside of a clean room.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates generally to semiconductor device fabrication, and more particularly to a method and apparatus for improving the reliability of semiconductor device fabrication.

[0002]

BACKGROUND OF THE INVENTION In the manufacture of semiconductor devices, great care must be taken to protect them from contaminants. Therefore, in the conventional semiconductor device manufacturing method, it is necessary to use expensive and sophisticated clean rooms for all stages of the manufacturing process. When a semiconductor device is processed in a contaminated environment, fine particles contaminate the device, causing a great loss in productivity and reliability of a completed device. The need for this constant clean room environment accounts for a large portion of the high cost of manufacturing semiconductor devices.

[0003]

In order to prevent contamination of semiconductor devices, expensive and complex vacuum transfer chambers are used whenever the device is removed from the clean room. Furthermore, semiconductor devices must always be housed in such a vacuum transfer chamber when outside of a clean room environment. Unfortunately, such vacuum transfer chambers are large and expensive, and are not ideal solutions to this problem.

Therefore, there is a need for a semiconductor device protection method that reduces the necessity of always accommodating semiconductor devices in a vacuum transfer chamber outside a clean room. It is an object of the present invention to protect semiconductor devices both inside and outside a clean room environment. It is another object of the present invention to increase the production yield of semiconductor manufacturing by reducing contamination of semiconductor devices at all stages of production.

[0005]

SUMMARY OF THE INVENTION The above and other objects are at least partially attained in a method and apparatus for protecting a semiconductor device using a self-molding protective enclosure. Is achieved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment, a film for protecting the surface of a semiconductor device by using a self-assembled enclosure is provided. This protective film allows the device to be removed from the clean room environment without causing excessive contamination to the device. The self-assembled enclosure comprises at least one self-assembled monolayer (SAM) deposited on the surface of the semiconductor device. This self-assembled monolayer inclusion is made by applying a solution containing molecules with heads consisting of surfactant groups. The surfactant groups self-assemble and bind to the surface of the semiconductor device. In particular, the surface-active groups are selected to bind to the surface of the semiconductor device. In an embodiment, the surfactant groups are selected to adhere to a silicon dioxide layer on the semiconductor device substrate. When such molecules self-assemble, they self-align such that their heads point toward the surface of the semiconductor and their tails point away from the surface, thereby forming a dense protective film over the semiconductor device.

[0007] Self-assembled self-assembly is an extremely ordered molecular assembly that can produce very thin organic films. "Extremely ordered" refers to the spatial structure of these molecules. This extremely orderly nature of these films results in high densities with few defects and a high degree of molecular alignment. In the present disclosure, self-assembly and self-assembly deposition are defined as a deposition of molecules in which a substantially uniform molecular structure is formed on a surface and the molecules are substantially perpendicular to the surface.

[0008] If desired or necessary, an additional self-assembled monolayer of inclusions can be applied. When the device is returned to a clean environment, or is in any other processable condition, the enclosure can be easily removed and the device returned to its original state. Turning now to the drawings for a more detailed description of the embodiments, FIG. 1 is a schematic side cross-sectional view of a portion of a semiconductor device 10. In one embodiment, the semiconductor device 1
0 includes the silicon (Si) substrate 12. The upper portion of the semiconductor element 10 has silicon dioxide (SiO 2) having an upper surface 16 of silicon dioxide.
₂ ) Including layer 14. In other embodiments, semiconductor substrate 12 comprises other suitable semiconductor elements, such as gallium arsenide (GaAs). The semiconductor element 10 shown is thus a substrate 12
It can be any semiconductor portion before, during or after the formation of the individual semiconductor elements in any of the manufacturing steps. The semiconductor device 10 is used to illustrate the device protection method and device according to the present invention.

FIG. 2 is a schematic side sectional view showing another stage in the manufacture of the semiconductor device 10. As shown in FIG. The first step in this embodiment is the deposition of a bonding layer 20 on the semiconductor device 10. Bonding layer 20
Works in this embodiment to couple the carrier element 10 with a protective enclosure to be applied later. The type of tie layer is selected to chemically bond to the top surface 16 of the semiconductor device 10 and the protective encapsulation. In the present embodiment used on the silicon substrate 12 having the silicon dioxide layer 14, the bonding layer is made of hydroxy (OH). In particular, the hydroxylate is chosen such that the head group forms a silicon-oxygen bond during self-assembly.

For semiconductor elements made of different types of materials, a coupling layer other than the coupling layer 20 can be selected. For example, if the semiconductor material system is gallium arsenide (GaAs)
If s) is included, a suitable tie layer comprises thiol (SH). More specifically, the bonding layer of the GaAs semiconductor substrate preferably comprises alkanethiol.

FIG. 3 is a schematic side sectional view showing another stage in the manufacture of the semiconductor device 10. With the bonding layer 20 applied to the semiconductor device 10, the next step in this embodiment is the deposition of a self-assembled protective fill 30. The protective encapsulation 30 chemically bonds to the semiconductor device 10 and effectively protects it from contamination. In this embodiment, protective encapsulation 30 includes at least one self-assembled monolayer encapsulation.

FIG. 4 shows molecules 40 of a self-assembled monolayer before being applied to a semiconductor device. In this embodiment, the molecule 4
0 is octadecyltrichlorosilane (OTS: octadecy)
ltrichlorosilane). Specifically, the OTS molecule 40
Consists of a head 42, a torso 44 and a tail 46. Head 4
2 comprises a surfactant group selected to bind to the semiconductor device. In this embodiment used on a silicon substrate, the surface-active group is composed of trichlorosilane (SiCl ₃ ). Head 4
If the two surface-active groups are SiCl ₃ , these molecules will self-assemble and form a tight molecular bond with the bonding layer on the surface of the semiconductor device. Also, if SiCl ₃ is used for the head portion 42, the surface of the semiconductor portion will not be contaminated.

The body 44 of the molecule 40 contains a series of hydrocarbon molecules. In this example, 18 hydrocarbon molecules, specifically C
H ₂ is used. Tail 46 preferably contains an element with low interfacial free energy (typically less than 1 kcal / mol), such as fluorine. Therefore, the terminal groups can be made of fluorocarbon molecules, for example CF _3. It goes without saying that other molecules having low interfacial free energy can also be used. Alternatively, the tail 46
Is optional, and all of them can be deleted.

When multiple molecules of the type shown in FIG. 4 are deposited on a semiconductor device, they self-assemble to form a protective enclosure. In a typical self-assembled, hydroxylated semiconductor portion octadecyl trichlorosilane in an organic solvent _{(OTS; CH 3 (CH 2} ) 17SiCl 3)
Introduced into the solution. After immersion, the semiconductor element is washed with water and dried. FIG. 5 shows the plurality of molecules 50 defining the protective encapsulation 30 (FIG. 3) after self-assembly on the semiconductor device 10. In particular, the plurality of molecules 50 form a self-assembled protective encapsulation film that is bonded to the semiconductor device 10 as a dense monolayer. Also in this case, each molecule 50 has a head 5
2, consisting of a trunk 54 and a tail 56. In this embodiment,
As the fill is deposited, the chlorine on the head 52 of each molecule 50 (see FIG. 4) is replaced by interfacial chemisorption with oxygen from the bonding layer 14 already deposited on the semiconductor device 10. The chlorine combines with oxygen from the bonding layer 14 and evaporates.
The remaining silicon-oxygen bonds are very strong, and cause the molecules 50 to be tightly bonded to the semiconductor device 10. In addition, hydrocarbons are laterally coupled by electrostatic forces and other forces. This bonding creates a chemically dense film, which results in a mechanically and chemically protective enclosure for the semiconductor device 10. By this process, the semiconductor element 10 is covered, and a self-assembled film forming a protective enclosure is obtained. The protective enclosure prevents other chemicals and contaminants from reaching the surface of the semiconductor device 10.

In an alternative embodiment for use in gallium arsenide (GaAs) semiconductor devices, suitable surface active groups include thiols. In particular, the self-assembled protective fill for GaAs is preferably octadecanethiol (OTD; CH ₃
(CH ₂ ) 17 SH). In this embodiment, the chemical composition of the body and tail groups is similar to that of the silicon semiconductor portion.

The protective encapsulation 30 created by the plurality of molecules 50 simultaneously forms a new surface structure on the semiconductor device 10. This surface structure has the properties of an element located at the tail 56 of the molecule 50. Thus, if the tail 56 is selected to have a low interfacial free energy, the surface of the fill will have a low interfacial free energy. In this embodiment, the tail 56 is fluorine (F) or polymers in the form of CF ₃ - -containing fluorine. The use of fluorine creates a surface with low interfacial free energy such that other particles do not readily adhere to the surface, or that any particles attached to the surface are only loosely bound to the surface. Other compatible elements with low interfacial free energy include chlorine and silicon. Therefore, the possibility that the semiconductor element 10 is contaminated is greatly reduced.

Other elements may be used for the tail 56. Alternatively, tail 56 can be omitted entirely. For example, larger molecules, such as fluorine-containing polymers, can be used as end groups to achieve desired interfacial properties.

Another advantage of the protective encapsulation 30 according to the present invention is that the surface to be produced is passivated in terms of its surface chemistry. As a result, the properties of this surface are stabilized by deactivation, especially against contamination by particulates.

FIG. 6 is a schematic side sectional view of another stage in the manufacture of the semiconductor device 10. In this embodiment, the second layer of the self-assembled monolayer is applied. In this embodiment, the end groups of the previously applied layer are preferably those that are bonded to subsequent layers. The next step is to add another tie layer 62 to the protective enclosure 30.
This is the step of applying Also in this embodiment, the bonding layer 62
Consists of hydroxy (OH).

FIG. 7 is a schematic side sectional view of another stage in the manufacture of the semiconductor device 10. With the second bonding layer 62 of FIG. 6 applied, a second film 72 of a self-assembled monolayer is applied. In this embodiment, the second film 72 is similar to the protective encapsulation 30, but it is possible to use layers having different or additional features if desired.
The second film 72 provides a thicker layer of protective encapsulation, further reducing the possibility of contaminants reaching the surface of the substrate. This process can be repeated as many times as desired, and the protection of the semiconductor device 10 is further enhanced by the additional self-assembled layer.

Thus, there is provided a protective enclosure for protecting the surface of a semiconductor device from contamination. This protective enclosure
The film can be removed at any time by standard manufacturing procedures, such as vaporizing in ultraviolet light or standard oxygen plasma. Thus, an effective protective encapsulation is provided that significantly improves the reliability of semiconductor manufacturing without requiring excessive increases in clean room costs. In addition, semiconductor elements can be removed from the clean room using this protective enclosure while reducing the risk of contamination.

Although specific embodiments of the present invention have been illustrated and described, other modifications and improvements will occur to those skilled in the art. Accordingly, it is desired that the invention not be limited to the specific forms illustrated herein, but that the appended claims intend to cover any modifications that do not depart from the spirit and scope of the invention.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a stage of manufacturing a semiconductor device according to the present invention.

FIG. 2 is a side sectional view showing a stage of manufacturing a semiconductor device according to the present invention.

FIG. 3 is a side sectional view showing a stage of manufacturing a semiconductor device according to the present invention.

FIG. 4 shows molecules used in the present invention.

FIG. 5 shows a self-assembled group of a molecule according to the present invention.

FIG. 6 is a side sectional view of a semiconductor portion according to the present invention.

FIG. 7 is a side sectional view of a semiconductor portion according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 semiconductor element 12 silicon (Si) substrate 14 silicon dioxide (SiO ₂ ) layer 16 upper surface of layer 14 20 bonding layer 30 self-assembled protective encapsulation 40 molecule of self-assembled monolayer 42 head of molecule 40 body 44 of molecule 40 Part 46 Tail of molecule 40 50 Molecule of protective enclosure 30 52 Head of molecule 50 54 Body of molecule 50 56 Tail of molecule 50 62 Bonding layer 72 Second membrane

Claims (3)

[Claims] A method for protecting a semiconductor surface of a semiconductor device during manufacture, comprising: a method of protecting a semiconductor surface of a semiconductor device;
6); and coating the semiconductor surface (16) with a self-assembled protective encapsulation (30). 2. A method for protecting a semiconductor surface of a semiconductor device during manufacture, comprising the steps of:
6) depositing a tie layer (20) on the semiconductor surface (16); and depositing a self-assembled protective fill (30) on the tie layer (20); The self-assembled protective enclosure (30) is connected to the tie layer (2).
Bonding to the semiconductor surface (16) via 0). 3. A protective encapsulation for protecting a surface of a semiconductor device during manufacture, comprising: a semiconductor surface (1) of a semiconductor device (10).
6); and a self-assembled fill (30) disposed on said semiconductor surface (16).