US20130302982A1

US20130302982A1 - Deposition method using a substrate carrier

Info

Publication number: US20130302982A1
Application number: US13/943,782
Authority: US
Inventors: Chun-Hsing Tung; Fei-Tzu Lin
Original assignee: United Microelectronics Corp
Current assignee: United Microelectronics Corp
Priority date: 2011-12-13
Filing date: 2013-07-16
Publication date: 2013-11-14
Also published as: US8534659B2; US20130149870A1

Abstract

A deposition method comprises steps as follows. An apparatus for performing a thin-film deposition process is firstly provided, and the apparatus comprises a cabinet, a substrate carrier and a deposition source. The substrate carrier is disposed in the cabinet and comprises a cover element and a supporting element having a through hole. The deposition source is disposed in the cabinet. A substrate is subsequently disposed on the supporting element in order to make a deposition surface of the substrate exposed from the through hole. The cover element is then engaged with the supporting element to secure the substrate therebetween. Next, a deposition vapor is provided from the deposition source to get in touch with the deposition surface.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional application of an application Ser. No. 13/323,941, filed Dec. 13, 2011. The entirety of the above-mentioned patent application are hereby incorporated by reference herein and made a part of this specification.

FIELD OF THE INVENTION

The present invention relates to a tool and applications thereof, and more particularly to a deposition method using a substrate carrier.

BACKGROUND OF THE INVENTION

A backside metal process is one of the key process steps for the fabrication of integrated semiconductor devices. Conventionally, a metal sputtering process or an electron beam deposition (EBD) process may be performed to form a metal film on the backside surface of a wafer in order to improve the heat depression problems of the integrated circuit (IC) formed on the active surface of the wafer opposite to its backside surface. In some cases, the metal film may further provide electrical connection functions to improve the wiring integrity of the IC.
In some typical backside metal process, at least one wafer is disposed on a carrier, and the active surface and backside surface of the wafer are exposed. The carrier is then disposed in a cabinet of a deposition apparatus pervaded by a metal source, whereby a metal film can be formed on the backside surface of the wafer. However, there are still some drawbacks, for example, since the backside metal process is carried out without shielding the active surface of the wafer, thus some metal ions may be deposited thereon, and these metal ions may be further oxidized to contaminate the active surface, such that wafer may be smudged and active surface discoloration may occur. These problems may get worse, especially in the course of some thermal reactions or at the time of vacuum release.
Therefore, there is a need of providing an advanced substrate carrier, an apparatus for performing a deposition process and a method applying thereof in order to prevent wafer discolored or smudged and improve the production yield of the integrated semiconductor devices formed on the active surface of the wafer.

SUMMARY OF THE INVENTION

Therefore, one aspect of the present invention is to provide a deposition method comprises steps as follows. An apparatus for performing a thin-film deposition process is firstly provided, wherein the apparatus comprises a cabinet, a substrate carrier and a deposition source. The substrate carrier is disposed in the cabinet and comprises a cover element and a supporting element having a through hole. The deposition source is disposed in the cabinet. A substrate is subsequently disposed on the supporting element in order to make a deposition surface of the substrate exposed from the through hole. The cover element is then engaged with the supporting element to secure the substrate therebetween. Next a deposition vapor is provided from the deposition source to get in touch with the deposition surface.
In one embodiment of the present invention, the substrate is a wafer, and the deposition vapor is a metal source vapor.
In one embodiment of the present invention, the step for engaging the cover element with the supporting element comprises steps of defining a space substantially airtight between the cover element, the supporting element and the substrate.
In one embodiment of the present invention, the deposition surface is a backside surface of the wafer, and the space is defined by the supporting element, the cover element and an active surface of the wafer.
In one embodiment of the present invention, the step of providing the apparatus further includes: configuring a base of the supporting element, the base having the through hole penetrating therethrough; and configuring a first annular flange of the supporting element, the first annular flange vertically protruding from a top surface of the base and surrounding the through hole.
In one embodiment of the present invention, the step of providing the apparatus further includes: configuring a shield plate of the cover element and a second annular flange of the cover element, the second annular flange protruding from the shielding plate; and configuring a protruding length of the second annular flange extending from the shielding plate substantially greater than a protruding length of the first annular flange extending from the base. Wherein the step of engaging the cover element with the supporting element to secure the substrate therebetween further comprises getting the second annular flange in touch with a portion of the base beyond the outer edge of the first annular flange.
In accordance with aforementioned embodiments, the present invention provides a substrate carrier used for performing a deposition method. The substrate carrier comprises a supporting element and a cover element, when the supporting element and the cover element are engaged with each other; a substrate can be secured therebetween. By using the cover element as a shielding mask to prevent the surfaces of the substrate which are undesired to be subject to a deposition process from getting in touch with the deposition vapor, the undesired contaminations and discoloration occurring on the substrate may be avoided and the production yield of the integrated semiconductor devices formed on the substrate may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:

FIG. 1A is an exploded view illustrating a substrate carrier according to one embodiment of the present invention;

FIG. 1B is a cross section view illustrating the assembly structure of the substrate carrier shown in FIG. 1A; and

FIG. 2 illustrates a cross sectional view of an apparatus for performing a deposition according to one embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A substrate carrier, an apparatus for performing a thin-film deposition process and a method applying thereof are provided to prevent the surfaces of a substrate which are undesired to be subject to a deposition process from discoloration due to the contamination of a deposition vapor. The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.
FIG. 1A is an exploded view illustrating a substrate carrier 10 according to one embodiment of the present invention. The substrate carrier 10 comprises a supporting element 100 and a cover element 120. The supporting element 100 is used to carry a substrate 11; the cover element 120 is used to be engaged with the supporting element 100, whereby the substrate 11 can be secured between the supporting element 100 and the cover element 120 for performing a deposition process.
In some embodiments, the deposition process may be a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, a sputtering process, a thermal evaporation process, an EBD process or an atomic layer deposition (ALD) process. 100201 The supporting element 100 and the cover element 120 may be composed by materials with thermal resistance. For example, in some embodiments of the present invention, the deposition is carried out in a high temperature substantially ranges from 300° C. to 400° C. , thus the supporting element 100 preferably may be a shelf structure made of stainless steel; and the cover element 120 may be composed by metal materials (such as stainless steel) or ceramics. The substrate 11 is preferable a semiconductor wafer, and for the purpose of clearly describing the embodiments, the substrate 11 will be referred as a wafer 11 thereinafter.
FIG. 1B is a cross section view illustrating the assembly structure of the substrate carrier 10 shown in FIG. 1A. The supporting element 100 has a base 100 a, a through hole 100 b and a annular flange 100 c, wherein the through hole 100 b penetrates through the base 100 a, and the annular flange 100 c vertically protruding from the base 100 a and surrounds the through hole 100 b.
In some embodiments of the present invention, the through hole 100 b is a circular through hole, and the annular flange 100 c is a circular flange 100 c. In addition, the annular flange 100 c has a diameter substantially greater than that of the wafer 11; and the through hole 100 b has a diameter substantially less than that of the wafer 11. Thereby, the wafer 11 can be disposed just on the portion of the base 100 a located between the annular flange 100 c and the through hole 100 b; and a deposition surface 11 a of the wafer 11 which is predetermined to be subject to a deposition can be exposed from the through hole 100 b. In the present embodiment, the deposition surface 11 a is the backside surface of the wafer 11. However, it should be appreciated that the number and shape of the through hole 100 b may vary in accordance with the practical need for performing the deposition process. In some other embodiments of the preset invention, a plurality of through holes 100 b with different shapes may be formed on the supporting element 100 for performing the deposition process.
For the purpose of convenient delivery and ease of operation, in some embodiments of the present invention, the supporting element 100 can further comprise a handle 102 fixed on the edge of the base 100 a, wherein the handle 102 may be an independent element fixed on the edge of the base 100 a by welding, clamping, embedding, tong-groove joining, adhering or other appropriate measures. Otherwise, in some other embodiments of the invention, the handle 102 may be a protruding portion extending from the base 100 a of the supporting element 100 rather than an independent element.
The cover element 120 has a shielding plate 120 a and an annular flange 120 b, wherein the annular flange 120 b vertically protrudes from the edge of the shielding plate 120 a and defines a cover surface 120 c on one side of the shielding plate 120 a. Similarly, for purpose of convenient delivery and ease of operation, the cover element 120 further comprises a holding rod 122 fixed on a surface of the shielding plate 120 a opposite to the cover surface 120 c. In some embodiments of the present invention, the holding rod 122 may be an independent element fixed on the surface of the shielding plate 120 a by welding, clamping, embedding, tong-groove joining, adhering and other appropriate measures. In some other embodiments of the present invention, the holding rod 122 may be, otherwise, a protruding portion extending from the surface of the shielding plate 120 a.
In the embodiments of the present invention, the cover element 120 is used to engage with the supporting element 100 in order to secure the wafer 11 between the supporting element 100 and the cover element 120. In the present embodiment, the way of engaging the supporting element 100 with the cover element 120 is directly disposing the shielding plate 120 a of the cover element 120 onto the base 100 a of the supporting element 100, whereby the cover surface 120 c of the cover element 120 can confront the wafer 11 disposed on the base 100 a of the supporting element 100.
Since the annular flange 120 b of the cover element 120 used to define the cover surface 120 c has a size substantially greater than that of the annular flange 100 c of the supporting element 100, in the present embodiment, thus when the cover element 120 is engaged with the supporting element 100, the cover surface 120 c of the cover element 120 can extend beyond the area surrounded by annular flange 100 c, so as to thoroughly cover the wafer 11 which is disposed on the base 100 a.
In addition, because the protruding length of the annular flange 120 b extending from the shielding plate 120 a is greater than the protruding length of the annular flange 100 c extending from the base 100 a, thus when the cover element 120 is engaged with the supporting element 100, the annular flange 120 b may get in touch with the portion of the base 100 a beyond the outer edge of the annular flange 100 c, and thereby a space S substantial airtight can be defined by the annular flange 120 b, the cover surface 120 c of the cover element 120, the base 100 a of the supporting element 100 and an active surface 11 b (opposite to the deposition surface 11 a) of the wafer 11.
However, in some other embodiments of the present invention, the protruding length of the annular flange 120 b extending from the shielding plate 120 a may be less than the protruding length of the annular flange 100 c extending from the base 100 a, thus when the cover element 120 is engaged with the supporting element 100, the annular flange 100 c may get in touch with the cover surface 120 c surrounded by the annular flange 120 b.
When the deposition surface 11 a of the wafer is subject to a deposition process, the active surface 11 b of the wafer 11 which is seal with in the space S should not be contaminated by the deposition vapor and wafer discoloration may not occur, and thereby the production yield of the semiconductor devices form on the active surface 11 b of the wafer 11 may be increased. This is because that the active surface 11 b of the wafer 11 is shielded by the annular flange 120 b of the cover element 120 and the base 100 a of the supporting element 100, thus the deposition vapor can be prevented from getting in touch with the active surface 11 b of the wafer 11.
However, it should be appreciated that, the main function of the substrate carrier 10 is to shield the active surface 11 b of the wafer 11 from being contaminated by the deposition vapor. Such that, only if the active surface 11 b of the wafer 11 can be effectively shielded, the space S defined by the supporting element 100, the cover element 120 and the active surface 11 b of the wafer 11 may not be essentially airtight. In some embodiments of the present invention, the annular flange 120 b of the cover element 120 may have at least one gap (not shown).
In addition, since the annular flange 100 c of the supporting element 100 and the annular flange 120 b of the cover element 120 are designed in corresponding to the profile of the substrate (wafer 11), thus the annular flanges 100 c and 120 b is generally designed as a ring-like structure having a cross section identical with the profile of the substrate. For example, in the present embodiment, the annular flanges 100 c and 120 b has a circular cross section identical to the circular profile of the wafer 11. Otherwise, in some other embodiments, the cross section of the annular flanges 100 c and 120 b may be designed as non-circular (not shown).
Besides, for the purpose of securing the cover element 120 on the supporting element 100, the substrate carrier 10 further comprises at least one fastening element 130 (see FIG. 1A) The fastening element 130 may be a turnbuckle, a nut and bolt, a clamp or other suitable elements. In the present embodiment, the fastening element 130 is a turnbuckle pivoted on the edge of the base 100 a of the supporting element 100 (shown in FIG. 1A), by which the shielding plate 120 a of the cover element 120 can be hooked up with the supporting element 100.
FIG. 2 illustrates a cross sectional view of an apparatus 200 for performing a deposition according to one embodiment of the present invention. The apparatus 200 comprises a cabinet 201, a plurality of substrate carriers 10 and a deposition source 202. The substrate carriers 10 are disposed on a hanger bracket 203 built in the cabinet 201. The deposition source 202 is disposed in the bottom of the cabinet 201 used to provide a deposition vapor 204, such as metal source vapor, during the deposition process.
For the purpose of evenly dispersing of the deposition vapor 204, in some embodiments, the apparatus 200 further comprises at least one rotatable shutter 205, whereby the concentration of the deposition vapor 204 pervaded with in the cabinet 201 can be well controlled. In addition, a plurality of different deposition sources may be disposed in the cabinet 201 and a plurality of the rotatable shutters 205 are also applied, thereby the deposition source 202 desired to be used for the deposition process can be selected by controlling the on-and-off of the corresponding rotatable shutters 205.
The method for performing the deposition process by utilizing the apparatus 200 comprises steps as follows: An apparatus 200 shown in FIG. 2 is firstly provided, wherein the apparatus 200 comprises a cabinet 201, a plurality of substrate carriers 10 and a deposition source 202. Each of the substrate carrier 10 comprises a cover element 120 and a supporting element 100 having a base 100 a and a through hole 100 b passing through the base 100 a. The deposition source 203 is also disposed in the cabinet 201.
A wafer 11 is subsequently disposed on the supporting element 100 in order to make a deposition surface 11 a of the wafer 11 exposed from the through hole 100 b. The cover element 120 is then engaged with the supporting element 100 to secure the wafer 11 between the supporting element 100 and the cover element 120. Next a deposition vapor 204 is provided from the deposition source 203, whereby the deposition vapor 204 can get in touch with the deposition surface 11 a of the wafer 11 which is exposed from the through hole 100 b, and meanwhile a metal thin film (not shown) can be formed on the deposition surface 11 a of the wafer 11.
In accordance with aforementioned embodiments, the present invention provides a substrate carrier used for performing a deposition. The substrate carrier comprises a supporting element and a cover element, when the supporting element and the cover element are engaged with each other; a substrate can be secured therebetween.
By using the cover element as a shielding mask to prevent the surfaces of the substrate which are undesired to be subject to a thin-film deposition process from getting in touch with the deposition vapor, the undesired contaminations and discoloration occurring on the substrate may be avoided and the production yield of the integrated semiconductor devices formed on the substrate may be improved.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.

Claims

What is claimed is:

1. A deposition method, comprising:

providing an apparatus, wherein the apparatus comprises:

a cabinet;

a substrate carrier, disposed in the cabinet and comprising a cover element and a supporting element having a through hole; and

a deposition source, disposed in the cabinet;

disposing a substrate on the supporting element in order to make a deposition surface of the substrate exposed from the through hole;

engaging the cover element with the supporting element to secure the substrate therebetween; and

providing a deposition vapor from the deposition source to get in touch with the deposition surface.

2. The deposition method according to claim 1, wherein the substrate is a wafer and the deposition vapor is a metal source vapor.

3. The deposition method according to claim 1, wherein the step for engaging the cover element with the supporting element comprises steps of defining a space substantially airtight between the cover element, the supporting element and the substrate.

4. The deposition method according to claim 3, wherein the deposition surface is a backside surface of a wafer, and the space is defined by the supporting element, the cover element and an active surface of the wafer.

5. The deposition method according to claim 1, wherein the step of providing the apparatus further comprises:

configuring a base of the supporting element, the base having the through hole penetrating therethrough; and

configuring a first annular flange of the supporting element, the first annular flange vertically protruding from a top surface of the base and surrounding the through hole.

6. The deposition method according to claim 5, wherein the step of providing the apparatus further comprises:

configuring a shield plate of the cover element and a second annular flange of the cover element, the second annular flange protruding from the shielding plate; and

configuring a protruding length of the second annular flange extending from the shielding plate substantially greater than a protruding length of the first annular flange extending from the base;

wherein the step of engaging the cover element with the supporting element to secure the substrate therebetween further comprises getting the second annular flange in touch with a portion of the base beyond the outer edge of the first annular flange.