JPH09241837A - Rolled product for target and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably increase reliability on the production of a target and to reduce unstability in the production indefinite in cause.

SOLUTION: This production is started from a coarse cast blank partially rolled according to necessary and passes the following continuous (1) to (4) stages: (1) an oxide layer applying the blank is removed, and a means of preventing its reformation is executed; (2) heat treatment in which precipitates contg. alloy elements present in an aluminum base metal are homogenized and formed into a soln. in a furnace having a nonoxidizing atmosphere is executed; (3) The homogenizing heat treatment is prolonged till the content of hydrogen reaches <0.05ppm under the condition in which the extraction of the greater part of hydrogen contained in the product is made possible and (4) the blank is subjected to rolling in accordance corresponding to the reduction of the thickness or cross section at least by 10%.

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a rolled product for a target and a method for manufacturing the same, and more particularly to a method for manufacturing a product made of aluminum or an aluminum alloy for forming a cathode sputter target. These targets are used in the metallization of various substrates, including the manufacture of integrated circuits.

[0003]

[Prior art]

Several techniques are already known for producing targets for cathodic sputtering. For example, French patent FR-B1-2 664 618 (= EP 0466617, = US
5160388), an AlSi alloy containing 0.05 to 2% by weight of Si is prepared from highly pure aluminum and, if necessary, other additive elements in order to obtain a target of fine particles. Process, the process of casting it into a billet or a disc, the process of carrying out the homogenization process peculiar to the invention, the process of punching the billet into a disc in the case of billet, and the process of performing deformation to reduce the product thickness And a step of performing a recrystallization treatment. Preferably, the billet pond is magnetically agitated during casting to refine the cast particles.

Furthermore, European application EP-A1-57300
The manufacturing method of the target described in 2 is 0.01 to 3 by weight.
%, Si, Cu, Ti, Pd, Zr, Hf and a process of forming an aluminum alloy containing 0.01 to 3% by weight of at least one element selected from the group consisting of rare earths and casting into a billet. A step of performing a first melt heat treatment at 500 to 600 ° C. for at least 30 minutes, a step of rapidly cooling the billet to ambient temperature, preferably within 1 minute, and rolling to form a target. Or the process of compressing the billet by forging, etc.,
The target was adjusted to 100 for 5 to 30 minutes in order to adjust the proportion of the solid solution of the added element to a value preferably between 50 and 90%.
To a second heat treatment at 500 ° C.

In this European application, it will be obvious to a person skilled in the art that the solid solution with a proportion of more than 50% thus obtained is unstable and will undergo at least this work due to heating by the cathodic sputter operation. Within the zone, the solid solution add-on element will necessarily transition to a more stable state below 50%.

[0007]

[Problems to be Solved by the Invention]

[0008] Cathode sputtering, whose principle is described abundantly in specialized technical literature, is of any kind regardless of whether it is refractory (heat resistant), whether it is an alloy, or whether it is conductive or dielectric. The material can be deposited on any type of substrate that can be vacuumed and lightly heated. This deposition technique has found a particularly large field of application for the coating of aluminum alloys on silicon plates and the production of integrated circuits.
For example, the fabrication of ultra-high integrated circuits, such as dynamic memory DRAMs with capacities in excess of 4 megabytes, requires the deposition of a very thin (approximately 1 micron) interconnect metal layer, which is then etched to a very thin (width) width. Lines (less than 0.5 microns) are formed to allow individual access to each location in memory.

Under these conditions, any damage to the metallization layer, which is close to the width of the interconnect line, becomes a serious defect during the etching of the interconnect circuit and must be discarded. I understand that it will not happen.

One of the most frequently found defects in metallization layers obtained by vacuum cathode sputtering from a metal target is the removal of fine particles on the target surface, which solid or liquid fine particles form a semiconductor substrate during metallization. Is to redeposit on. The size of these particles is generally between a few tenths of a micron and a few microns, most often 1
To 5 μm.

In the case of previous generations of integrated circuits, where the etching width was a few microns, most of the particles thus redeposited on the underlying metallization do not lead to significant etching defects and are discarded for this reason. The failure rate of the metallized substrate produced was acceptable.

On the contrary, in the present and future generations of ultra-integrated circuits, for example, in the DRAM memory of 16 megabytes or more, the etching width becomes extremely narrow, and the line width becomes 10.
It became a few microns (currently about 0.2 to 0.5 microns). Under these conditions, it peels off the target,
The extremely fine particles redeposited on the semiconductor substrate are a major cause of defects in integrated circuits, and this defect causes a great deal of damage to the global electronics industry every year.

Of course, it is a great problem for the electronic industry to lose this defect, or at least to suppress it, so that the electronic industry needs a great deal of research and development to investigate the cause of this defect and take countermeasures against it. It goes without saying that we are working hard.

On the other hand, the known target manufacturing methods, in particular the methods mentioned above, cannot solve this problem and the targets manufactured by the prior art have a rather unstable performance and are also of acceptable quality. Some cannot, and no clear correlation has been established between the physicochemical properties of the target and its performance of use.

A first object of the present invention is to significantly increase the reliability of target manufacturing. Therefore, we aim to overcome unexplained manufacturing instability.

This method is based on the particle firing rate and the number and size of defects (generated from shrinkage cavities) in a target metal in which the active portion is formed of ultra-high purity aluminum or ultra-high purity aluminum-based alloy. There is a correlation between poor cohesion, microcracks, micropores, etc.) and is based on the fact that the Applicant accidentally discovered.

The manufacturing method according to the invention is the most general,
It usually seeks to solve the problems imposed by using only the most economical techniques in this field.

A further object of the invention is also a target which is characterized by a low number of defects (defective aggregation) per dm ³ .

[0019]

[Means for Solving the Problems]

The production method of the present invention is a method for producing a product made of aluminum or an aluminum alloy for forming a cathode sputter target from a blank formed by casting a liquid metal having a composition corresponding to aluminum or an aluminum alloy. Defect is less than 100, size is dm
^In order to obtain a target equal to 0.1 mm per ^{3 and} having less than 0.03 ppm of dissolved or included hydrogen, the manufacturing method is characterized by the following successive steps: 1) removing the oxide layer coating the blank And a step of carrying out a means for preventing its re-formation; 2) an alloy existing in the aluminum base material under the condition that the surface of the product is not oxidized in a furnace having a non-oxidizing atmosphere. Performing a heat treatment to homogenize and solubilize the precipitate containing the element; and 3) from the beginning, under the conditions that make it possible to extract most of the hydrogen contained in the product, the hydrogen content is 0.05
until less than ppm, preferably less than 0.03 ppm,
Prolonging the homogenizing heat treatment; 4) subjecting the blank to rolling corresponding to a thickness or cross-section reduction of at least 10%.

This main measure makes it possible to obtain a target which meets the criteria which the applicant has found to be important and which exhibits properties which correlate with sufficient application properties.

In the step 1), the means for preventing the reformation of the oxide layer is not strictly understood, and especially in the step 3) of degassing of this method, the diffusion of hydrogen becomes a major obstacle to the removal. It is meant to implement measures to prevent the significant reformation of the oxide layer, ie the thick oxide layer.

The rolling in step 4) is also aimed at refilling the holes that have lost gas contents in step 3) of degassing.

Preferably, the blank is a cast rough billet obtained in a manner known per se (cylindrical semi-finished product, generally a few meters in length).

After step 3), preferably immediately before the rolling step 4), the billet is cut into thin pieces (cut perpendicularly to the billet to form a generally disc-shaped thin piece),
Each slice constitutes a target blank which is subjected to rolling in step 4).

Although the billet according to the invention is generally circular in cross section, it does not exclude billets of other geometric cross sections, eg rectangular.

According to the invention, the blank used at the beginning of step 1) is a rough casting, or the same casting, partially after cold- or hot-rolling, optionally after homogenization treatment. It is composed of rolled blanks.

In this case, the partially rolled blank may be partially rolled to crush the billet forming the rough casting to a final thickness of at least 1.1 times the target finish thickness of the target. It can be cut into billets having a circular or rectangular cross section obtained by rolling.

The main advantage of such a modification lies in the shortening of the degassing process 3) and / or the improvement of the degassing efficiency, which has been shortened because the thickness of the degassing blank has been previously reduced.

According to a modification of the present invention, after the rolling of step 4), a recrystallization heat treatment step for stabilizing the grain size and a step of giving the target a final dimension can be continued. The process is also well known.

According to step 1) of this method, it is important to remove the natural layer of hermetic oxide from the blank.

The removal of the oxide layer is carried out by dry working the surface of the blank and immediately afterwards transferring it to the heat treatment furnace.

Preferably, the oxide can also be removed by dissolving it in an aqueous solution of an acid having a pH of less than 3.5. The surface thus treated is then covered with a thin film of a low boiling metal. The reformation of the oxide layer on the blank surface is prevented.

To form the metal thin film, preferably, cadmium or zinc in an aqueous solution of an acid is added at pH 3.
Less than 5, preferably deposited by electrolysis with a cathodic potential applied to the aluminum or alloy blank.

In this way, the blank covered with the metal thin film can be temporarily stored and handled without risk.

During the heat treatment, in steps 2) and 3) of the method, the blank is treated in a non-oxidizing atmosphere at a temperature above 450.degree. Suitably, the residual pressure of the oxidizing gas in said atmosphere is less than 0.13 Pa. Oxidizing gas is generally oxygen O ₂ , water vapor H ₂ O or carbon dioxide C
By O ₂ , other slightly reactive gases such as nitrogen N ₂ are also included. Preferably, the heat treatment is performed in vacuum or under an atmosphere of a neutral gas having a low residual content of oxidizing gas,
It is preferably carried out under purified argon.

When the blank is covered with a low boiling metal layer, preferably the heat treatment furnace adheres to the surface of the blank and evaporates when the temperature of the blank rises, the metal of the thin film metal. A cold trap maintained below 200 ° C. is provided which is capable of condensing vapor.

Generally, the homogenization of step 2) is carried out at a temperature below the eutectic temperature of the aluminum alloy and the hydrogen extraction of step 3) above this eutectic temperature but of the homogeneous alloy Since it is carried out at a temperature lower than the solidus temperature, the total work time for homogenization and degassing is shortened. However, this method of working, although desirable, achieves the intended purpose: homogenization of the chemical composition and redissolution of the metal precipitate, and subsequent hydrogen content of the metal. It is not necessary for extraction.

After the blank is heat-treated and degassed in step 3), the blank is finally rolled in step 4) to form a blank by billet casting, which corresponds to the general treatment according to the invention. Reducing the thickness or cross section by rolling the blank before or after cutting it into flakes having the shape of a disc.

The above-mentioned rolling is in the shape of a disk (a thin piece of billet)
Forging, squeezing, rolling of << flat >> products, including
Alternatively, it can include extruding the billet, cutting into thin plates or discs after extrusion, and the like.

Even after the applicant has been able to characterize the target necessary to guarantee the final formulation, the difficulty of the problem to be solved does not diminish. Because, in continuous air casting, it is extremely difficult to obtain a cast product in which micropores and microshrinkage voids are completely eliminated, and the solidification interval is long, that is, between the solidification start temperature of the alloy and its effective temperature at the end of solidification. This is especially the case for aluminum alloys with a large difference between, but this applies to the silicon alloys used for the usual types of specific targets.

In the continuous or semi-continuous casting, since the solidification rate is high, this solidification actually causes the composition of the metal to continue during the growth of the resinous crystals between the nucleus of each resinous crystal and its periphery. Change.

At the end of solidification, the residual liquid enriched with alloying elements is trapped between the resinous crystals of the alloy which has already solidified. The final shrinkage of the solidification in turn leaves voids or microshrinks, especially in the spaces between the resinous crystals.

On the other hand, the hydrogen present in the liquid metal or the hydrogen absorbed during the casting by the reaction between the liquid metal and the moisture in the atmosphere is almost insoluble in the solid aluminum, so that the molecules in this residual cavity are This contraction is transformed into micropores containing the entrapped gas as it tends to be released in the form of a gas, which causes the pressure in the cavity to reach and even exceed atmospheric pressure.

During the subsequent homogenization treatment of the alloy, especially before rolling, the hydrogen, which has not yet diffused into these microcavities, has been dissolved in the metal in atomic form in the metal, especially by the bonding of the particles, Diffuse towards this defect, where it agglomerates.

Therefore, the hydrogen-filled microcavities (microconstriction cavities or micropores), which have been referred to as "cohesion failure" and have a pressure that can significantly exceed the atmospheric pressure, are formed in the subsequent rolling process. It is difficult to refill and produces crush defects with transverse dimensions (due to crushing) greater than the initial defects, oriented parallel to the direction of deformation of the metal.

In addition, some alloys, especially 0.5% silicon.
For alloys containing more than, the structure of the continuously cast crude product formed at the end of solidification, contains crude intermetallic precipitates, which are often much more than the aluminum matrix. It is particularly concentrated in areas that are stiff and have many micro-shrinks and micro-pores formed at the end of solidification.

These precipitates, which are hard and often brittle, combine with micro-shrinkage cavities or micro-holes and also prevent the formation of re-welds of these defects during the rolling of the product, and also of this rolling. It may even promote crack propagation and even amplify them during these mechanical deformations.

Finally, the present invention allows the use of aluminum and aluminum alloys or industry standard and economical equipment, as well as use under standard operating conditions.

Thus, according to the manufacturing method of the present invention,
The blank formed by casting, and optionally by subsequent pre-rolling, is 100 per dm ^3.
The present invention does not require any special means at this stage, which includes internal cohesion failure significantly exceeding 10000 nm, cohesion failure having a size exceeding 100 μm, and may further include melted or contained hydrogen significantly exceeding 0.03 ppm. It is shown that. On the other hand, the implementation of the means of the present invention requires 10 per dm ^3.
Contains less than 0, often less than 10 cohesive defects (unless the initial blank contains large amounts of refractory inclusions, typically 5 mg / kg or more),
It makes it possible to obtain rolled products containing less than 03 ppm of hydrogen.

Depending on the nature of the alloy or the casting conditions, among others, the blanks formed by casting and optionally pre-rolling may contain only 10-100 / dm ^{3 of} internal agglomeration defects of more than 100 microns in size. And containing more than 0.03 ppm of molten or entrapped hydrogen, and in this case by the process according to the invention an internal cohesion failure of less than 10 / dm ³ and 0.03 pp.
Rolled products for targets containing less than m of molten or entrapped hydrogen are obtained, but likewise above, where the content of refractory inclusions such as oxides, nitrides, carbides and even graphite is high.

[0052]

【Example】

[0053]

Example 1 Production of a blank for processing into a target:

In a high-purity graphite crucible, 1% by weight of silicon and 0.5% by weight of copper having a metal impurity content of less than 10 ppm in an ultra-high-purity aluminum base were added by air dissolution. 450 kg of this alloy was manufactured.

This metal was cast into a billet having a coarse diameter of 137 mm by electromagnetic stirring continuous casting without degassing.

During casting, the metal was continuously filtered through a perforated plate of alumina of a nature selected to remove most of the inclusions above 100 microns in size.

The gas (hydrogen) content of the metal thus cast was taken from a thin section of solid billet by solid sample dissolution by the classical method of hydrogen content extraction using an instrument under the trademark STROEHLEIN. It was measured at.

This hydrogen content averaged 0.17 ppm with a standard deviation of 0.03 ppm among different flakes taken from the cast billet, and all measurements were carried out by the same worker on the same day.

Examination of thin pieces taken from the cast billet with high frequency (10 Mhz) ultrasonic waves revealed the presence of numerous agglomeration defects (micro shrinkage foci and micro pores) of more than 100 micron, and 100 micron. Agglomeration failure of more than 30 on average per dm ³ of inspected metal
It reached 0 and exceeded 1000 / dm ³ at the center of the flakes, which is the most concentrated area of defects.

Additional information on ultrasonic examination is contained in the French patent application No. 9601990 by the applicant.

The surface of the slices so inspected by ultrasound is subjected to optical microscopy to find a large local concentration of silicon precipitates with a size of more than 10 microns, in most cases of more than 50 microns, as well as a high copper content. The presence of numerous micropores, including metal tube precipitates, was revealed.

The structure of the cast product was thus characterized and a first round slice of a billet 137 mm in diameter and 600 mm in length was taken.

First, in order to remove the cast skin formed by the thick oxide layer on this slice of billet,
The skin was lightly peeled in a manner known per se while pouring water with added water-soluble oil. In this way, the diameter of the billet was reduced to 132 mm.

This round slice of billet was then cut to 0 .. by classical inspection according to the French standard AIR 9051.
It was confirmed that there was no defect (echo amplitude) corresponding in size to the 7 mm flat bottom hole.

Process 1): After this preliminary confirmation and drying, the round slice of this billet was dry reprocessed with a "diamond" bite without lubricant (so-called "diamond" processing), and the diameter was reduced to 131 mm.

Step 2): Immediately after the dry reworking, a billet slice was immediately introduced into a heating furnace previously evacuated to a vacuum of 0.13 Pa (10 ^-3 Torr), and then 8 kPa.
Very pure argon with an oxygen and water vapor content of less than 10 ppm (by volume) at a pressure of (60 Torr) is introduced into the furnace.

Then, at a temperature rising rate of 50 ° C./hour, 51
The billet slices were heated to 0 ° C. and maintained at this temperature for 8 hours.

Step 3): During the solidification of the billet, after this initial holding (homogenization step) to redissolve any precipitate formed out of equilibrium, the temperature is gradually increased over 4 hours. The temperature was raised again to 565 ° C. The billet slices were kept at this temperature for 120 hours, removed from the furnace, and
Air cooled to ambient temperature in hours (forced ventilation).

Step 4): Next, a round slice of this billet having a length of 600 mm was cut into ten thin pieces having a thickness of about 55 mm and having almost the same thickness. After surface finishing, each flakes was inspected on both sides with high frequency ultrasonic waves of 15 Mhz. Each slice examined in this way is a process 1)
It had porosities almost comparable to those of the cast crude billets as obtained at the end of the above, with a large number of pores larger than 100 microns. In addition, microscopic examination performed on one side of each flake with a thickness of 55 mm revealed no large precipitates of silicon greater than 20 microns or copper-enriched precipitates. A cylindrical specimen with a diameter of 10 mm was extracted from the 5 slices into which another 5 slices were inserted, in order to measure the hydrogen content by the method described above. This measured content is less than 0.03 ppm, and the content of the casting crude billet is 0.17 ppm, which means that the hydrogen initially contained was reduced by 80% or more. Another 5 slices with a thickness of 55 mm were pressed and cold rolled to a thickness of between 20 and 50 mm (20/30/4
0/45 / 50mm), then frequency 15M
It was examined by ultrasonic waves at Hz. From this examination, considering the preliminary verification of this ultrasonic measurement method, the crushed flakes with a thickness of less than 45 mm (specimen thickness 20/30/40 mm) have a flat bottom hole of 0.1 mm. It has been found that there are few defects of equal size exceeding the size, more precisely less than 30 cohesive defects per dm ³ of metal. On the other hand, in the case of the flakes having the thicknesses of 45 and 50 mm, the cohesion failure was far more numerous, and was generally about 100 as compared with 300 of the original billet.

[0070]

Embodiment 2

The procedure of Example 1 is reproduced except that the furnace atmosphere is air in steps 2) and 3). In this case, an airtight, thick layer of oxide having a thickness of more than 5 nanometers was formed on the surface of the processed billet. It was found that the hydrogen content measured in step 4) was between 0.08 and 0.17 ppm, much higher than that obtained in Example 1. In the optical microscope examination, the holes present in the alloy after the heat treatment of steps 2) and 3) are only slightly closed during the rolling of step 4),
It has been shown that the number of cohesive defects above 100 microns is approximately 150 per dm ³ .

[0072]

Embodiment 3

After the "diamond" processing in step 1), in an aqueous solution of 2 g of cadmium chloride per liter, added with the amount of hydrochloric acid necessary to adjust the pH of the solution to a value below 3.5. The procedure of Example 1 was reproduced, except that the billet was sliced. After waiting for 2 minutes, a current of 5 amperes was applied for 2 minutes between the slices of billet used for the cadmium anode and cathode. This electrolytic deposition operation deposited cadmium with a thickness of 0.1 to 0.15 micron. As an experiment, the pieces thus coated were kept at 40 ° C. for 1 week in an atmosphere of saturated steam.
Then, after placing in a heat treatment furnace (steps 2) and 3)), Example 1
Exactly the same heat cycle. In the case of Example 3, in order to prevent the cadmium vapor released during the reheating of the billet slices from condensing there and preventing redeposition on the billet slices and the furnace wall during final cooling, the furnace was 150 ° C
Equipped with a cryogenic trap maintained at a temperature below. On the other hand, in order to prevent any contamination of liquid cadmium from entering the joints of the billet sliced particles, when increasing the temperature in step 2), the total amount of cadmium adhering to the billet sliced in advance in the cryotrap. The temperature was held at 290 ° C. for 6 hours in order to evaporate and recondense. At this time, after steps 2) and 3), the hydrogen content is 0.03 pp.
It was confirmed that it was less than m. Under this condition, the finish rolling process of step 4) completely closed most of the holes originally existing in the cast rough billet, and after the process 4), the number of aggregation defects exceeding 100 microns was averaged. It has also been found that it is possible to obtain from 10 to 20 flakes per dm ^{3, a} much smaller number of flakes than obtained in Example 1.

[0074]

Embodiment 4

A) Starting Blank Manufacture A cast rough billet slice obtained from the same casting as in Example 1 was sampled. A 150 mm long cylindrical billet is lightly stripped to a 137 mm diameter.
It was changed from mm to 132 mm. It is then subjected to air homogenization at 510 ° C. for 8 hours, then rapidly cooled to 350 ° C. and pre-rolled by pressing at this temperature parallel to the casting axis, with a thickness of 50 mm and a diameter of approximately 23 mm.
It was transformed into a 0 mm disk.

B) Working on target After cooling to ambient temperature, this disk was dry worked on its flat surface to a thickness of 48 mm and immediately transferred to a furnace,
A vacuum of 0.13 Pa (ie 10 ⁻³ Torr) was applied. The disc was first maintained at 510 ° C. for 8 hours, then the temperature was gradually increased to 550 ° C. over 4 hours and the disc was kept at this temperature for 36 hours. After being taken out from the heat treatment and rapidly cooled to the ambient temperature with air, the disk was subjected to finish rolling with a cross mill, and the thickness was changed from 48 mm to 25 mm by passing three times in succession to an average diameter of about 320 mm. Next, roll this rolled disc into 32
It was subjected to a recrystallization treatment with air at 0 ° C. for 1 hour, followed by a diamond finishing treatment to give a final thickness of 20 mm and a diameter of 305 mm. When tested with ultrasonic waves at a frequency of 15 MHz, most of the defects larger than 100 microns present in the casting blank disappeared after the entire manufacturing process and the final density of the defects in the finished target was ,
It has been found that there are less than 10 defects with a size of more than 100 microns per dm ^{3 of} metal. After being brazed and connected to a copper carrier plate, this disk has extremely fine etching with an extremely high degree of integration (etching width 0.35 micron).
Used as a target for cathodic sputtering for metallization of integrated circuits. The obtained results were evaluated as excellent (the circuit failure rate due to this cause is less than 3%), judging from the frequency of occurrence of minute arcs that would cause particles that interfere with etching in the subsequent process to adhere to the integrated circuit. .

[0077]

[Other embodiments]

In particular, the aluminum alloys described above and containing 1% by weight of silicon and 0.5% by weight of copper as a main additive are particularly prone to the formation of microscopic shrinkage cavities and micropores. As will be readily understood by a person skilled in the art, the manufacturing methods carried out with the same tests have the same advantageous effects, and with the same advantageous effects, all of the many aluminum alloys used for the metallization of electronic circuits, such as the binary alloy Al--Si, Or Al-Cu, or more complex alloys Al-Cu-Ti, Al-Si-
Although it can be applied to Ti, as well as Al-Si-Cu-Ti, etc., special conditions of heat treatment have to be adapted to prevent phenomena such as "homogenized burns". It is a local melting phenomenon in the area of parts rich in meltable eutectic. In this way, the content of hydrogen taken up in the blank for targeting the alloys could be significantly reduced, which also significantly reduces the rolling reocclusion of defects present in the casting rough part. This target was able to reduce the tendency of this target to release solid or liquid particles upon use.

[Results Obtained]

In each of Examples 1 to 3, the process
The flakes obtained after 5) were used as targets and examined in a metallization comparison test as described in our French patent application 96-01990. In use, the targets obtained from the blanks treated according to the invention almost entirely had a very low failure rate due to redeposition of particles from the target onto the metallized integrated circuits (less than 5% failure). ).

Claims (16)

[Claims] 1. A method of manufacturing a rolled product for an aluminum or aluminum alloy target for forming a cathode sputter target from a blank formed by casting a liquid metal having a composition corresponding to aluminum or an aluminum alloy, comprising: A manufacturing method characterized by a continuous process of: 1) performing a means for removing the oxide layer covering the blank and preventing its re-formation; 2) in a furnace having a non-oxidizing atmosphere, A step of carrying out a heat treatment for homogenizing and solubilizing precipitates containing alloying elements present in the aluminum base material under the condition that the surface of the product is not oxidized; 3) included in the product from the beginning The hydrogen content is less than 0.05 under the conditions that allow most of the hydrogen to be extracted.
until less than ppm, preferably less than 0.03 ppm,
Prolonging the homogenizing heat treatment; 4) subjecting the blank to rolling corresponding to a thickness or cross-section reduction of at least 10%. 2. The manufacturing method according to claim 1, wherein the blank is a cast coarse billet having a cylindrical or rectangular cross section, and after the step 3) and before the rolling step 4),
The billet is cut into thin pieces and each thin piece is processed
A manufacturing method, characterized in that a target blank to be rolled in 4) is constructed. 3. The manufacturing method according to claim 1, wherein the blank used in step 1) is a partially rolled blank, forming the rough casting blank, homogenized if necessary, and having a circular cross section. Alternatively, it is a blank obtained by crushing or rolling a rectangular rough cast billet to a final thickness of 1.1 times or more the target finish thickness of the target. 4. The manufacturing method according to claim 1, wherein after the rolling in step 4), a recrystallization heat treatment step for stabilizing the grain size and a final dimension are given to the target. A manufacturing method characterized in that a final processing step is continued. 5. The manufacturing method according to claim 1, wherein the oxide layer is removed by dry-processing the surface of the blank,
Immediately thereafter, the method is carried out by transferring to the heat treatment furnace. 6. The manufacturing method according to claim 1, wherein the oxide layer on the surface of the blank dissolves the oxide in an aqueous solution of an acid having a pH of less than 3.5. The method, characterized in that the surface which has been removed and treated in this way is then covered with a thin film of a low-boiling metal to prevent the reformation of the oxide layer on the blank surface. 7. The method according to claim 6, wherein cadmium or zinc in an aqueous solution of an acid is electrolyzed at a pH of less than 3.5, preferably by applying a cathodic potential to the aluminum or alloy blank. A manufacturing method, characterized in that it is attached. 8. The manufacturing method according to claim 5, wherein the residual pressure of the oxidizing gas in the atmosphere is less than 0.13 Pa. 9. The manufacturing method according to claim 8, wherein the heat treatment is performed in a vacuum. 10. The manufacturing method according to claim 8, wherein the heat treatment is carried out under an atmosphere of a neutral gas having a low residual content of oxidizing gas, preferably under purified argon. And a manufacturing method. 11. The manufacturing method according to claim 6, wherein the heat treatment furnace adheres to the surface of the blank, and the metal of the thin film is adhered to the surface of the blank. A manufacturing method comprising a low temperature trap capable of coagulating metal vapor and maintained at a temperature of less than 200 ° C. 12. The manufacturing method according to claim 1, wherein the homogenization in step 2) is performed at a temperature lower than the eutectic temperature of the aluminum alloy, and the hydrogen extraction in step 3) is performed in this step. A manufacturing method characterized by being carried out at a temperature above the melting temperature but below the solidus temperature of the homogeneous alloy. 13. The manufacturing method according to claim 1, wherein the blank used for starting step 1) has an internal cohesion failure of more than 100 and a size of more than 100 microns per dm ^3. A manufacturing method characterized in that the molten or entrapped hydrogen exceeds 0.03 ppm. 14. The manufacturing method according to claim 1, wherein the blank used to start the step 1) has a size of 1 or less.
Internal cohesion failure of more than 00 micron is 10 per dm ^3.
-100, and more than 0.03 ppm of molten or included hydrogen is included. 15. Internal cohesion failure is 100 per dm ^3.
Rolled product for a target, characterized in that it is produced by the production method according to claim 13 containing less than 0.03 ppm of molten or entrapped hydrogen. 16. Internal cohesion failure of less than 10 / dm ³ .
A rolled product for a target, characterized in that it is produced by the production method according to claim 14 containing less than 0.03 ppm of molten or entrapped hydrogen.