CN1567547A - Modification method for metallic layer - Google Patents
Modification method for metallic layer Download PDFInfo
- Publication number
- CN1567547A CN1567547A CN 03142956 CN03142956A CN1567547A CN 1567547 A CN1567547 A CN 1567547A CN 03142956 CN03142956 CN 03142956 CN 03142956 A CN03142956 A CN 03142956A CN 1567547 A CN1567547 A CN 1567547A
- Authority
- CN
- China
- Prior art keywords
- metal level
- modifying
- barrier layer
- heat treatment
- described metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
Abstract
The invention reveals a metallic layer modifying method, firstly providing a semiconductor substrate; forming a first metallic blocking layer on the surface of the substrate; forming a metallic layer on the surface of the first metallic blocking layer; then forming a second one on the surface of the metallic layer; and at last performing a modifying program, which includes: 1, in heat treatment mode including baking or quickly cooling, modifying the metallic layer; 2, in processing mode of nitrogen containing gas, modifying the metallic layer. The modifying program can be performed: 1, before forming the metallic layer; 2, after forming the metallic layer; 3, after forming the second metallic Ti blocking layer, and 4, after forming the second metallic titanium nitride blocking layer.
Description
Technical field
The present invention relates to a kind of method of manufacture of semiconductor, particularly a kind of method for modifying of metal level.
Background technology
Metal carbonyl conducting layer is played the part of epochmaking role in semiconductor technology, also be a very important techniques and accurately inerrably each layer metal carbonyl conducting layer is integrated in the chip.The development need of metal current conductor layer improves its reliability as far as possible, dwindles its size and increases its processing procedure permission.
Yet, several difficulty being arranged in the manufacturing technology of metal carbonyl conducting layer, must be improved.Because the reflectivity of metal carbonyl conducting layer is quite high, high-intensity reflectivity can cause exposure to aim at the generation difficulty in follow-up little shadow (photolithography) processing procedure.Therefore, the surface of metal carbonyl conducting layer can form an anti-reflecting layer (anti-reflective coating) usually, titanium nitride for example, and the intensity of reflected light when reducing little shadow exposure can improve the micro-photographing process permission.
In addition, the normal at present plain conductor material of using mostly is albronze (Cu/Al alloy) or copper alusil alloy (Cu/Al/Si alloy), and copper aluminium (CuAl but often takes place in processing procedure easily
2) separate out the problem of (precipitate).The generation that cause poisonous residue when the subsequent etch metal conducting layer is understood in separating out of copper aluminium, and the barrier layer that residue can cause being positioned at the metal level below breaks, and forms short circuit.
And, in the plain conductor layer deposition process residual stress (stress) and surface irregularity and easily cause the problem of photoresistance avalanche, all be to be badly in need of the direction improved at present.
In view of this, in order to address the above problem, main purpose of the present invention is to provide a kind of method for modifying of metal level, applicable to the manufacturing of semiconductor alloy lead (conductivewiring).
Summary of the invention
One of purpose of the present invention is to provide a kind of method for modifying of metal level, and is inhomogeneous to avoid metal level, to avoid copper aluminium (CuAl
2) problem of separating out (precipitate) takes place, and the metal conducting layer problem of short-circuit takes place.
Two of purpose of the present invention is to provide a kind of method for modifying of metal level, and to reduce the difference of metal layer reflectivity and reflectivity, favourable follow-up little shadow is made.
The present invention is characterized in 1. with heat treatment mode, comprise baking or cooling fast, the upgrading metal level.2. with nitrogenous gas processing mode upgrading metal level.In addition, these upgrading modes can be performed in 1. and form before the metal level, 2. form after the metal level, 3. form after the second metal barrier layer titanium, 4. form after the second metal barrier layer titanium nitride.
For achieving the above object, the present invention proposes a kind of method for modifying of metal level, and the step of the method mainly comprises:
At first, provide the semiconductor substrate; Then, form one first metal barrier layer in above-mentioned substrate surface; Then, form a metal level in the above-mentioned first metallic barrier laminar surface; Then, form one second metal barrier layer in above-mentioned layer on surface of metal; At last, implement a heat treatment process.
As previously mentioned, above-mentioned first metal barrier layer and above-mentioned second metal barrier layer respectively by storehouse titanium (Ti)/titanium nitride (TiN) is constituted, and above-mentioned metal level is albronze (Cu/Al alloy) or copper alusil alloy (Cu/Al/Si alloy).
According to the present invention, above-mentioned heat treatment process can the quench cooled mode carry out or carry out with roasting mode.
According to the present invention, above-mentioned heat treatment process can be performed in to form after the above-mentioned metal level or be performed in and form the above-mentioned second metal barrier layer titanium nitride (TiN) afterwards.
According to the present invention, the temperature of above-mentioned heat treatment process is about 200-400 ℃.
According to the present invention, the variations in temperature of above-mentioned quench cooled is by room temperature about 23 ℃, and about 5-10 rises to about 350 ℃ with temperature in second, then, keeps about 50-70 second, cools the temperature to about 23 ℃ of room temperature in second at about 30-100 at last.
Again, for obtaining above-mentioned purpose, the present invention proposes a kind of method for modifying of metal level again, and the step of the method mainly comprises:
At first, provide the semiconductor substrate; Then, form one first metal barrier layer in above-mentioned substrate surface.Then, form a metal level in the above-mentioned first metallic barrier laminar surface; Then, form one second metal barrier layer in above-mentioned layer on surface of metal.At last, implement a nitrogenous gas handling procedure.
According to the present invention, above-mentioned nitrogenous gas handling procedure can be performed in and form after the above-mentioned metal level, or is performed in the above-mentioned second metal barrier layer titanium nitride (TiN) of formation afterwards.
According to the present invention, above-mentioned nitrogenous gas comprises nitrous oxide (N
2O) or nitrogen (N
2).
The invention provides a kind of method for modifying of metal level, inhomogeneous to avoid metal level, to avoid copper aluminium (CuAl
2) problem of separating out (precipitate) takes place, and the metal conducting layer problem of short-circuit takes place.
The invention provides a kind of method for modifying of metal level, to reduce the difference of metal layer reflectivity and reflectivity, favourable follow-up little shadow is made.
Description of drawings
Fig. 1 is the processing procedure profile according to a preferred embodiment of metal level method for modifying of the present invention.
Fig. 2 is the processing procedure profile according to a preferred embodiment of metal level method for modifying of the present invention.
Fig. 3 is the processing procedure profile according to a preferred embodiment of metal level method for modifying of the present invention.
Fig. 4 is the processing procedure profile according to a preferred embodiment of metal level method for modifying of the present invention.
Symbol description
The semiconductor-based end of 100-;
104-first metal barrier layer;
The 1041-titanium;
The 1042-titanium nitride;
The 106-metal level;
The S100-heat treatment process;
S102-nitrogenous gas handling procedure;
108-second metal barrier layer;
The 1081-titanium;
The 1082-titanium nitride.
Embodiment
For above-mentioned purpose of the present invention, feature and advantage can be become apparent, preferred embodiment cited below particularly, and conjunction with figs. are described in detail below:
Embodiment 1, below please refer to the processing procedure profile of Fig. 1 to Fig. 4, illustrates according to a preferred embodiment of the present invention.
At first, please refer to Fig. 1, semiconductor substrate 100 is provided, its material for example is a silicon (Si), and its top can form any required semiconductor subassembly, for example MOS transistor, resistance, logic module etc., but herein for simplicity of illustration, only with 100 expressions of smooth substrate.In narration of the present invention, " substrate " speech comprises established assembly and the various coatings that cover on the wafer on the semiconductor crystal wafer; " substrate surface " speech comprises the superiors of being exposed of semiconductor crystal wafer, for example silicon wafer surface, insulating barrier, plain conductor etc.
Then, please refer to Fig. 2, form one first metal barrier layer 104 in substrate 100 surfaces.First metal barrier layer 104 can be made of titanium (the Ti)/titanium nitride (TiN) of storehouse, utilizes physical vaporous deposition (physical vapor deposition; PVD) or chemical vapour deposition technique (chemical vapor deposition; CVD) form.The about 90-110 of process temperatures ℃ is target with the Titanium earlier, forms the about 130-170 of thickness of titanium 1041, and then under the Titanium target feeding nitrogen and form the about 180-220 of thickness of titanium nitride 1042.
Then, please refer to Fig. 3, form a metal level 106 in first metal barrier layer, 104 surfaces.Metal level 106 can comprise albronze (Cu/Al alloy) or copper alusil alloy (Cu/Al/Si alloy), its composition for example is atomic percent Al99.5%, Cu0.5%, atomic percent Al98.5%, Cu0.5% and Si1% can utilize physical vapor deposition (PVD) or chemical vapour deposition technique (CVD) to form.The about 270-330 of process temperatures ℃, the about 2500-4000 of the thickness of metal level 106.
At this moment, after forming metal level 106, can implement main upgrading step of the present invention, implement a heat treatment process S100.Heat treatment process S100 can carry out or carry out in the quench cooled mode by roasting mode, and temperature is about 200-400 ℃.And this heat treatment process S100 can implement down in nitrogenous compression ring border, for example nitrous oxide (N
2O) or nitrogen (N
2).This heat treatment process S100 can prevent copper aluminium (CuAl
2) separate out (precipitate).The generation that cause poisonous residue when the subsequent etch metal conducting layer is understood in separating out of copper aluminium, and the barrier layer that residue can cause being positioned at the metal level below breaks, and forms short circuit.This heat treatment process S100 can also improve the metal level uniformity, avoids taking place the metal conducting layer problem of short-circuit, can effectively control the uniformity of metal layer reflectivity again, the execution that favourable follow-up little shadow is made.
At last, please refer to Fig. 4, form one second metal barrier layer 108 in metal level 106 surfaces.Second metal barrier layer 108 can be made of titanium (the Ti)/titanium nitride (TiN) of storehouse, utilizes physical vapor deposition (PVD) or chemical vapour deposition technique (CVD) to form.The about 90-110 of process temperatures ℃ is target with the Titanium earlier, forms the about 90-110 of thickness of titanium 1081, can carry out an electricity slurry then simultaneously and handle and a gas treatment (for example nitrogenous gas), so that titanium 1081 nitrogenize.Then, under the Titanium target, feed nitrogen again and form the about 650-750 of thickness of titanium nitride 1082.And titanium nitride 1082 can be simultaneously as anti-reflecting layer (anti-reflectioncoating).
According to the present invention, the method for modifying of present embodiment is the heat treatment process of step S100, and heat treatment process S100 can be performed in after the formation metal level 106, or is to be performed in after the titanium nitride 1082 that forms second metal barrier layer.
And, according to the present invention, the method for modifying of present embodiment is the heat treatment process of step S100, can also cooperate an electricity slurry processing or a gas treatment (for example nitrogenous gas) to carry out simultaneously, and execution is in proper order after forming the second metal barrier layer titanium nitride 1082.
The variations in temperature of quench cooled is by room temperature about 23 ℃ according to the present invention, in second, temperature is risen to about 350 ℃ at about 5-10, then, keeps about 50-70 second, cools the temperature to about 23 ℃ of room temperature in second at about 30-100 at last.
Similarly, below please cooperate the processing procedure profile of Fig. 1 to Fig. 4, illustrate according to another preferred embodiment of the present invention.
At first, please refer to Fig. 1, semiconductor substrate 100 is provided, its material for example is a silicon (Si), and its top can form any required semiconductor subassembly, for example MOS transistor, resistance, logic module etc., but herein for simplicity of illustration, only with 100 expressions of smooth substrate.In narration of the present invention, " substrate " speech is to comprise established assembly and the various coatings that cover on the wafer on the semiconductor crystal wafer; " substrate surface " speech comprises the superiors of being exposed of semiconductor crystal wafer, for example silicon wafer surface, insulating barrier, plain conductor etc.
Then, please refer to Fig. 2, form one first metal barrier layer 104 in substrate 100 surfaces.First metal barrier layer 104 can be made of titanium (the Ti)/titanium nitride (TiN) of storehouse, utilizes physical vapor deposition (PVD) or chemical vapour deposition technique (CVD) and forms.The about 90-110 of process temperatures ℃ is target with the Titanium earlier, forms the about 130-170 of thickness of titanium 1041, and then under the Titanium target feeding nitrogen and form the about 180-220 of thickness of titanium nitride 1042.
Then, please refer to Fig. 3, form a metal level 106 in first metal barrier layer, 104 surfaces.Metal level 106 can comprise albronze (Cu/Al alloy) or copper alusil alloy (Cu/Al/Si alloy), its composition for example is atomic percent Al99.5%, Cu0.5%, atomic percent Al98.5%, Cu0.5% and Si1% can utilize physical vapor deposition (PVD) or chemical vapour deposition technique (CVD) and form.The about 200-400 of process temperatures ℃, the about 2500-4000 of the thickness of metal level 106.
At last, please refer to Fig. 4, form one second metal barrier layer 108 in metal level 106 surfaces.Second metal barrier layer 108 can be made of titanium (the Ti)/titanium nitride (TiN) of storehouse, utilize physical vapor deposition (PVD) or chemical vapour deposition technique (CVD) and form, the about 90-110 of process temperatures ℃, be target with the Titanium earlier, form the about 90-110 of thickness of titanium 1081, and then under the Titanium target feeding nitrogen and form the about 650-750 of thickness of titanium nitride 1082.And titanium nitride 1082 can be simultaneously as anti-reflecting layer (anti-reflection coating).
According to the present invention, the method for modifying of present embodiment is the nitrogenous gas handling procedure of step S102, and nitrogenous gas handling procedure S102 can be performed in before the formation metal level 106, or form after the metal level 106, or be performed in after the formation second metal barrier layer titanium 1081, or be to be performed in to form after the second metal barrier layer titanium nitride 1082.
According to the present invention, the method for modifying of present embodiment is the nitrogenous gas handling procedure of step S102, and nitrogenous gas handling procedure S102 can cooperate a heat treatment process to carry out simultaneously, can be performed in and form (forming after the first metal barrier layer titanium nitride 1042) before the metal level 106, or form after the metal level 106, or be performed in after the formation second metal barrier layer titanium 1081, or be to be performed in to form after the second metal barrier layer titanium nitride 1082.
According to the present invention, the method for modifying of present embodiment is the nitrogenous gas handling procedure of step S102, and nitrogenous gas handling procedure S102 can cooperate an electricity slurry handling procedure to carry out simultaneously, can be performed in and form (forming after the first metal barrier layer titanium nitride 1042) before the metal level 106, or be performed in after the formation second metal barrier layer titanium 1081, or be to be performed in to form after the second metal barrier layer titanium nitride 1082.
Upgrading program of the present invention comprises 1. with heat treatment mode, comprises baking or quench cooled, the upgrading metal level.2. with nitrogenous gas processing mode upgrading metal level.Embodiment is illustrated in preamble respectively, and right various upgradings can use enforcement separately, can also merge to use to implement.
Though below described preferred forms of the present invention in conjunction with the accompanying drawings in detail; but be not in order to limit scope of the present invention; for those skilled in the art in this area; can make various modifications and changes; and do not deviate from scope of the present invention and essence; therefore, protection scope of the present invention only is defined by the claims.
Claims (21)
1, a kind of method for modifying of metal level is characterized in that, may further comprise the steps:
The semiconductor substrate is provided;
Form one first metal barrier layer in described substrate surface;
Form a metal level in the described first metallic barrier laminar surface;
Form one second metal barrier layer in described layer on surface of metal; And
Implement a heat treatment process.
According to the method for modifying of the described metal level of claim 1, it is characterized in that 2, described first metal barrier layer and described second metal barrier layer are made of titanium (the Ti)/titanium nitride (TiN) of storehouse respectively.
According to the method for modifying of the described metal level of claim 1, it is characterized in that 3, described metal level is albronze (Cu/Al alloy) or copper alusil alloy (Cu/Al/Sialloy).
According to the method for modifying of the described metal level of claim 1, it is characterized in that 4, described heat treatment process is to carry out with roasting mode.
According to the method for modifying of the described metal level of claim 1, it is characterized in that 5, described heat treatment process is to carry out in quench cooled (quench) mode.
According to the method for modifying of the described metal level of claim 1, it is characterized in that 6, described heat treatment process is to be performed in to form after the described metal level.
7, according to the method for modifying of the described metal level of claim 2, it is characterized in that, described heat treatment process be performed in form described second metal barrier layer titanium nitride (TiN) afterwards.
According to the method for modifying of the described metal level of claim 1, it is characterized in that 8, described heat treatment process is to implement down in the nitrogen containing atmosphere environment.
9, according to the method for modifying of the described metal level of claim 1, it is characterized in that, implement an electricity slurry in the time of described heat treatment process and handle.
According to the method for modifying of the described metal level of claim 1, it is characterized in that 10, the temperature of described heat treatment process is roughly 200-400 ℃.
According to the method for modifying of the described metal level of claim 5, it is characterized in that 11, described quick cooling program is that 5-10 makes temperature rise to 350 ℃ substantially by 23 ℃ of cardinal principles in second, keeps about 50-70 second in 350 ℃ of cardinal principles, temperature is dropped to 23 ℃ substantially again.
12, a kind of method for modifying of metal level is characterized in that, may further comprise the steps:
The semiconductor substrate is provided;
Form one first metal barrier layer in above-mentioned substrate surface;
Form a metal level in the above-mentioned first metallic barrier laminar surface;
Form one second metal barrier layer in above-mentioned layer on surface of metal; And
Implement a nitrogenous gas handling procedure.
According to the method for modifying of the described metal level of claim 12, it is characterized in that 13, described first metal barrier layer and described second metal barrier layer are made of the titanium (Ti) of storehouse/titanium nitride (TiN).
According to the method for modifying of the described metal level of claim 12, it is characterized in that 14, described metal level is albronze (Cu/Al alloy) or copper alusil alloy (Cu/Al/Sialloy).
According to the method for modifying of the described metal level of claim 12, it is characterized in that 15, described nitrogenous gas handling procedure is to be performed in to form before the described metal level.
According to the method for modifying of the described metal level of claim 12, it is characterized in that 16, described nitrogenous gas handling procedure is to be performed in to form after the described metal level.
According to the method for modifying of the described metal level of claim 12, it is characterized in that 17, described nitrogenous gas handling procedure is to be performed in to form the above-mentioned second metal barrier layer titanium (Ti) afterwards.
According to the method for modifying of the described metal level of claim 12, it is characterized in that 18, described nitrogenous gas handling procedure is to be performed in to form the above-mentioned second metal barrier layer titanium nitride (TiN) afterwards.
According to the method for modifying of the described metal level of claim 12, it is characterized in that 19, described nitrogenous gas comprises nitrous oxide (N
2O) or nitrogen (N
2).
According to the method for modifying of the described metal level of claim 12, it is characterized in that 20, described nitrogenous gas handling procedure is to implement simultaneously with a heat treatment process.
According to the method for modifying of the described metal level of claim 12, it is characterized in that 21, described nitrogen handling procedure is to handle simultaneously with an electricity slurry to implement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03142956 CN1567547A (en) | 2003-06-12 | 2003-06-12 | Modification method for metallic layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03142956 CN1567547A (en) | 2003-06-12 | 2003-06-12 | Modification method for metallic layer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1567547A true CN1567547A (en) | 2005-01-19 |
Family
ID=34471216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 03142956 Pending CN1567547A (en) | 2003-06-12 | 2003-06-12 | Modification method for metallic layer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1567547A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101567330A (en) * | 2009-06-04 | 2009-10-28 | 上海宏力半导体制造有限公司 | Method for preventing wiring metal from raising |
| CN101645415A (en) * | 2009-06-24 | 2010-02-10 | 上海宏力半导体制造有限公司 | Method for manufacturing metal connecting line |
| CN103632957A (en) * | 2012-08-23 | 2014-03-12 | 上海华虹宏力半导体制造有限公司 | Manufacturing method for semiconductor chip first layer metal barrier layer |
| CN103632931A (en) * | 2012-08-13 | 2014-03-12 | 上海华虹宏力半导体制造有限公司 | Metal aluminum silicon copper sputtering technological method |
| CN104124204A (en) * | 2013-04-28 | 2014-10-29 | 无锡华润上华科技有限公司 | Method for improving aluminum residue in semiconductor process flow |
| CN108847410A (en) * | 2018-06-21 | 2018-11-20 | 武汉新芯集成电路制造有限公司 | Improve the method for bond pad surface defect and the manufacturing method of pad |
-
2003
- 2003-06-12 CN CN 03142956 patent/CN1567547A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101567330A (en) * | 2009-06-04 | 2009-10-28 | 上海宏力半导体制造有限公司 | Method for preventing wiring metal from raising |
| CN101645415A (en) * | 2009-06-24 | 2010-02-10 | 上海宏力半导体制造有限公司 | Method for manufacturing metal connecting line |
| CN103632931A (en) * | 2012-08-13 | 2014-03-12 | 上海华虹宏力半导体制造有限公司 | Metal aluminum silicon copper sputtering technological method |
| CN103632931B (en) * | 2012-08-13 | 2016-11-02 | 上海华虹宏力半导体制造有限公司 | Metallic aluminium copper silicon sputtering technology method |
| CN103632957A (en) * | 2012-08-23 | 2014-03-12 | 上海华虹宏力半导体制造有限公司 | Manufacturing method for semiconductor chip first layer metal barrier layer |
| CN104124204A (en) * | 2013-04-28 | 2014-10-29 | 无锡华润上华科技有限公司 | Method for improving aluminum residue in semiconductor process flow |
| CN108847410A (en) * | 2018-06-21 | 2018-11-20 | 武汉新芯集成电路制造有限公司 | Improve the method for bond pad surface defect and the manufacturing method of pad |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1311540C (en) | Method of manufacturing semiconductor device | |
| CN1428840A (en) | Semiconductor device and mfg. method thereof | |
| CN1755943A (en) | Display device provided with semiconductor element and manufacturing method thereof | |
| CN101030552A (en) | Processing method of integrated circuit, metal-insulator-metal capacitor formation method | |
| CN1551691A (en) | Organic electroluminescent device and method for fabricating the same | |
| CN1117889C (en) | Plasma intensified chemical vapour deposition device and method for making said deposition | |
| CN1828832A (en) | Laser apparatus and manufacturing method of thin film transistor using the same | |
| CN1719582A (en) | Prepare the method for polysilicon membrane and prepare the method for semiconductor device with it | |
| CN1466190A (en) | Method for forming copper metal line | |
| CN1267969C (en) | Manufacturing method for semiconductor device | |
| CN1192426C (en) | Copper wiring | |
| CN1567547A (en) | Modification method for metallic layer | |
| CN1918719A (en) | Gallium nitride-based compound semiconductor light-emitting device | |
| CN1917167A (en) | Method of fabricating metal plug, and contact window | |
| CN1184687C (en) | Semiconductor device and manufacture method thereof | |
| CN1127759C (en) | Method for mfg. semiconductor device | |
| CN1705118A (en) | Ultraviolet blocking layer | |
| CN1243377C (en) | Method for making mixed copper internal connection stracture | |
| CN1897280A (en) | Semiconductor structure and its forming method | |
| CN1183581C (en) | Method for manufacturing titanium oxide layer | |
| CN1956172A (en) | Film transistor substrate and its manufacturing method | |
| CN2741182Y (en) | Semiconductor | |
| CN1427465A (en) | Manufacturing method of metal interconnector | |
| CN1744777A (en) | Laser induced thermal imaging method and a method of fabricating organic light emitting display | |
| CN1448995A (en) | Method for forming stack type dielectric layer on semiconductor base with metallic pattern |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |