TW201133712A - Method for exposing through-base wafer vias for fabrication of stacked devices - Google Patents

Abstract

An effective method for forming through-base wafer vias for the fabrication of stacked devices, such as electronic devices, is described. The base wafer can be a silicon wafer, in which case the method relates to TSV (through-silicon via) technology. The method affords high removal rates of silicon under appropriate conditions.

Description

201133712 VI. INSTRUCTIONS: Cross-references to the relevant applications No. 61/247,149 of the U.S. Provisional Patent Application Serial No. 61/247,104 and 09/30/2009, filed on Dec. 09/30/2009. interest. FIELD OF THE INVENTION The present invention is directed to the art of passing through a base wafer technology, and more specifically to thinning the back side of a base wafer to be assembled on the wafer in a stacked device, for example, a stacked product. A preformed through hole buried therein is previously exposed in the bulk circuit wafer. A specific example of a through-base wafer technology is the case where the base wafer is a germanium wafer, in this case the technique is referred to as through-via via (TSV) technology. The present invention is directed to an improved method suitable for inducing a through-substrate technique that utilizes chemical mechanical planarization (CMP) to provide a useful exposed metal via and a high removal rate for removal of the removed wafer material (eg,矽). This method provides a relatively long exposed metal via length and a high Shishi removal rate under appropriate conditions. [Prior Art] Semiconductor devices such as integrated circuits (ICs), also known as integrated body a μ.

Ba sheets typically include dielectric layers, metal line circuits, transistor switch formations, and memory features, as well as capacitors and other integrated circuit electrical devices that make complete operational imaginary or memory devices. Multilayer circuit traces, Codex, Mainfield or aluminum or copper, are patterned on the dielectric layer substrate 201133712. There are many types of layers that can be polished by CMP, for example: tantalum nitride; interlayer dielectrics (ILD), such as hafnium oxide and low-k films, including carbon-doped oxides; metal layers such as tungsten , copper, Ming, etc., which are used to connect the active device; barrier layer materials such as titanium, titanium nitride, buttons, nitride buttons, precious metals, and the like. Semiconductor wafer fabrication typically involves hundreds of individual operations on the surface of a germanium wafer that are carried out for extended periods of time. Chemical mechanical planarization (Chemical Mechanical Polishing, CMP) suitable for planarization of semiconductor substrates is now well known to those skilled in the art and has been described in numerous patents and publications. In a typical CMP process, a substrate (e.g., a wafer) is brought into contact with a rotating polishing pad attached to a platen. The CMP slurry ' typically a mixture of abrasive and chemically reactive, is supplied to, through or adjacent to the mat during the CMP treatment of the substrate. During the process, the mat (fixed to the platen) and the substrate are rotated, and the wafer carrying system or polishing head is pressed against the substrate (downward force). Due to the action of the downward force and the rotational movement of the mat relative to the substrate, the slurry is subjected to the planarization (polishing) treatment by chemical and mechanical interaction with the planarized substrate film. The method continues to polish until the desired film on the substrate is removed and the general purpose is to effectively planarize the substrate. Typically, the metal CMP slurry contains an abrasive material such as yttria or alumina suspended in an oxidizing aqueous medium. 3D integration is expected to reduce system formation by direct stacking and interaction of integrated circuit wafers that may utilize a single technology to make a single system. It is understood that the interconnects are constructed of small and deep through-wafer vias in the form of metal (e.g., copper) studs. The vias are generally vertical (relative to the back side of the wafer) electrical connectors that connect different general horizontal circuit layers and, in the context of the present invention, electrically interconnect the circuits on different integrated circuit wafers. One of the technologies capable of achieving 3D stacking is thinning of the base wafer, and a semiconductor circuit (integrated circuit) is disposed on the base wafer. Advantageously, the thinning technique results in a longer and stronger through-hole extending from the back of the wafer after the back of the wafer is thinned. In order to minimize wafer breakage and damage that may occur during this large scale process, the base wafers are often 3 Å to 8 Å-μm thick. At the end of the known deposition/patterning/removal polishing process in the art of forming an integrated circuit on the front side of the wafer, the base of the wafer through which the pre-formed through-holes are projected is thinned, Thereby the through hole is exposed. The base crystal is thinned by removing the base wafer material (e.g., germanium in the wafer processing case) from the back side of the wafer. This would involve bonding the front side of the wafer containing the integrated circuit to the carrier wafer and then grinding the back side of the wafer while the wafer is temporarily glued to the carrier and then CMp to approximately 10 to 5G micron thickness. The thinning exposes or further exposes conductive vias that extend at least partially through (e.g., completely through) the base wafer. The electrically conductive conductive portions of the exposed vias are very long compared to conventional via technology because the vias must compensate for the wafers and may also be inhomogeneities in the adhesive layer. Necessary, because · processing, especially Shi Xi: According to history, the rate is very limited. However, wafer delamination and destruction, and the destruction of the grinding wheel have become a back-grinding of the Shixi wafer. 201133712 Unfortunately, but not a rare problem. This problem is particularly problematic because the wafer represents the end product of many complex assembly and quality control steps, and the failure of these crystals represents a considerable economic loss. Moreover, the destruction of the grinding wheel results in considerable downtime of the production line and additional economic losses. What is needed is a CMP method that can polish a base wafer material at a high rate (e.g., in a germanium wafer case) such that the grinding step can be eliminated or reduced. Even in the method of grinding the backside material during the grinding step, the use of the same rate of removal CMP allows the manufacturer to include less material needed to grind from the back side of the wafer. In contrast to the above-described CMP applications, the present invention utilizes cMP to remove bulk materials, such as germanium, from the back side of the round, rather than individual films or metallization, as described more fully below. Previous prior art in the field of the invention includes: US 2 〇〇 9/〇 156 〇〇 6 and US 2010/0081279 〇 [Summary of the Invention] The present invention relates to techniques for causing penetration through a base wafer (for example, applied in this case) An improved method of through-wafer via (TSV) technology for wafers or wafers that provides a longer via extending from the back side of the polished wafer, wherein the via has reduced and small after CMP processing The amount of tailing and high removal rate. One embodiment of the present invention is a method of fabricating a base wafer for constructing a package including at least two integrated circuit wafers, at least from the base wafer The method includes: a) providing a first base wafer having a front side and a back side, wherein the front side 3 package 201133712 includes an integrated circuit disposed on the first base wafer, the eight-liter S-based wafer includes at least a conductive via hole' the at least one conductive via hole includes a conductive metal and extends at least partially through the base wafer from a front surface of the base wafer b) a back side of the base wafer and a polished And the CMP slurry contacts and licks the I wafer & back side until exposed or further exposed at least - conductive vias, wherein at least 4 calls of a downward force are applied during polishing. In this particular embodiment, an organic amine based compound is not required. The slurry used in the method for preparing a base wafer, which is used for the base wafer

The assembly of a two- or more stacked integrated Levy B circuit day wafer or stacking device is constructed to provide a high base wafer material, such as 矽 or / and rolled 矽, removal rate. In a specific embodiment, the slurry comprises: 1) a liquid carrier; 2) a C2-C6 organic diamine 'for example between 2% and 6% by weight 'preferably 1% to 4% , for example, between and between 2% and 4%, for example between 〇33% and 361%; 3) abrasives, for example high purity oxygen cutting, For example, an oxygen cut between 2% and 1% by weight, more usually between 3% and 6%; and 4) at least one metal chelating agent. In one embodiment, the backside of the base wafer can be polished at a rate of at least 10,000 angstroms per minute of the master knife clock using a method of using the first CMP slurry at a rate of 6 psi. There is a micro-sense, body example 10, using the first CMP slurry method to polish the first base wafer at a rate of at least 12,000 angstroms per minute under a downward force of 6 psi. Japanese yen. In a specific embodiment, the method of using the first CMP slurry of 201133712 can polish the first base crystal at a rate of at least 16,000 (four) per minute under a 6" downward force. The efficacy of the present invention is high. Base wafer removal rate because a large amount of base material is often removed. In one embodiment, the invention is a method of fabricating a base wafer for constructing a wafer comprising at least two integrated circuits. The at least one of the integrated circuit wafers is from the base wafer, the method comprising: a) providing a first base wafer having a front side and a back side, wherein the front side comprises a first base disposed An integrated circuit on the wafer and the base wafer includes a parent conductive via, the at least one conductive via comprising a conductive metal and extending at least partially through the base wafer from a front surface of the base wafer; b) Contacting the back side of the base wafer with the polishing pad and the cmp slurry, and c) polishing the back side of the base wafer until exposed or further exposed at least one conductive via hole' wherein at least 4 psi is applied during polishing The force of the force. In a specific embodiment, the present invention is an assembly for constructing a wafer including a singular-to-integral circuit wafer. At least the NMOS of the integrated circuit wafer is from the base wafer, the method comprising: a) providing a front side And a first base wafer on the back side, wherein the front side scoop comprises an integrated circuit disposed on the first base wafer and the base wafer package has at least one conductive through hole, the at least one conductive through hole comprising Conductive metal and extending at least partially through the base wafer from the front surface of the base wafer; b) fixing the front side of the base wafer having the integrated circuit thereon to the 201133712 piece; C) making the back side of the base wafer The I side is also in contact with the polishing pad and the first CMP slurry, the first CMP slurry comprising: 1) a liquid carrier; 2) a C2-C6 organic diamine; 3) an abrasive; and 4) to > a metal nutrient, and d) polishing the back side of the base wafer until exposed or further exposed at least - conductive through hole 'at at least ιο, 埃 埃 at a downward force of 6 psi The first CM wafer is transferred at the rate using the first CMp slurry. [Embodiment] The CMP method utilized in the present invention involves chemically planarizing the back side of a base wafer (e.g., tantalum wafer) using a CMP tool during processing through the base wafer. The problem with conventional CMP methods is polishing the crystal. The through hole formed during the round back side may extend, for example, 4 to 8 microns above the back side of the wafer. The polishing pad exerts a strong mechanical action on the metal through hole, and the through hole itself hinders the The mat affects any effective grinding action on the cerium oxide near the through hole by the abrasive in the slurry. As a result, a considerable thickness of yttrium oxide protrudes along the through hole, blocking the conduction on the through hole. And creating a mechanical property that is unfavorable to the through hole. Preferably, the through hole formed by the method of the present invention has a metal having at least 1.5 micrometers, preferably at least 2 micrometers protruding beyond the top of the 201133712 tailings 'often copper metal Out of the top of the tailings. Of course, there are some holes that are longer than others. In some embodiments of the invention, the tail extends less than 75% of the path along the through hole as measured from the back side of the wafer. If the through hole has a protrusion of 1 μm and a useful coverage of 5 μm, the tail is 5 microns high. The tail is found to protrude from the back side of the polished wafer and the ® tt is adjacent to the residual flaw of the exposed metal via. The extended metal via prevents the yttria material adjacent to the via from being removed during the CMP at the same rate as the enthalpy adjacent the via. The extended metal through-hole prevents the polishing pad from contacting the oxidized stone and prevents the CMP slurry from actively contacting and abrading the oxidized tail. When a substrate containing both tantalum and metal occurs, a lower amount of the tailings slag is provided during the CMP treatment to expose the metal vias to provide relatively long exposed metal vias (e.g., copper vias). This exposed metal region is longer, rather than shorter, after the CMP process, and is advantageous in most programs that pass through the base wafer via (e.g., Tsv) process and subsequent fabrication of the stacked device. However, not only the absolute height of the tail of the yttrium oxide is a key point in assembly. Using the slurry described herein, the manufacturer can change the corner profile of the portion of the screen. Preferably, the cerium oxide tail ends at an intermediate point along the through hole, but even if the ytterbium tail is really so high, it is preferred to have a very steep slope along the side of the through hole instead of having Shallow slope. Some through holes are very thick, for example, 60 microns thick, so the ratio of the thickness of the tail to the through hole is less important. Regarding the through hole having a thickness of 2 μm or less, the ratio of the thickness of the tail to the height of the through hole is more important. Preferably, when measured at a half height of the stroke from the base of the wafer to the top of the through hole, the thickness of the tail is calculated from the outer circumference of the 201133712 through the plane parallel to the back surface of the wafer. Extending, less than one third of the diameter of the through hole itself. The improved method limits the CMP treatment of the back side of the wafer under the following conditions: 1) the strong chemically active paste described herein, 2) the higher downward force described herein is preferably 4 psi to 1 〇 psi, for example 5 psi to 8 psi, optimally about 6 psi or about 7 psi, 3) low pressure disc and head 卩 rotational speed as described herein, each having an independent of 18 rpm to 60 rpm, more preferably Use a softer polishing pad from 20 rpm to 40 rpm or alternatively between 3 rpm and 60 rpm, for example between about 27 rpm and about 35 rpm. 'Better from 45 shore A to about 5 Shore A, preferably 45 Shore A to about 70 ShoreA, for example 55

Shore A to 66 Shore A hardness values. Furthermore, it is advantageous to have a polishing enthalpy compression ratio of between 8 vol% and 2 vol%, for example between 1 () vol% and 16 vol%. The base wafer, for example, yttrium oxide, has a removal rate of greater than 10,000 angstroms per minute at a downward force of 6 psi, often at least 12 angstroms per minute at a downward force of 6 psi The rate, and in the preferred embodiment, is at a rate of at least 16 angstroms per minute at a downward force of 6 psi. The efficacy of the present invention requires a high base wafer removal rate because a large amount of base material is often removed. Generally, t (4) the selectivity of the base wafer material when compared to copper is greater than 2 〇: for example, greater than · water and water and soluble in water as explained below, more appropriate liquid loading Agents include, but are not limited to, or a mixture of organic compounds dispersed in water. 201133712 Different organic solvents can be used alone or in combination with water as a liquid carrier. The Cz-C6 organic diamine can be any organic diamine having carbon, nitrogen and hydrogen atoms and having between 2 and 6 carbon atoms. In a specific embodiment, the organic diamine is one having two amine groups on an adjacent carbon atom, such as, for example, ethylenediamine or 1,2-diaminopropane. In a preferred embodiment, the diamine comprises ethylenediamine, consists essentially of ethylenediamine, or consists of ethylamine. At least one metal chelating agent is present in the CMP slurry composition utilized during the CMP process of the process according to the invention. Suitable chelating agents that can be added to the slurry composition include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), N-ethylethylamine monoacetic acid, cyanotriacetic acid, diethylenetriaminepentaacetic acid, ethanol Glycerate, Aminoacetic acid, N-Tris(hydroxymethyl)decylglycine (triCine), citric acid, 2,3-butanedipine (dimethylglyoxime), carbonic acid胍 and its mixture. Advantageously, the slurry can additionally comprise at least one non-polymeric nitrogen-containing material (amines, hydroxides, etc.). Suitable non-polymer gas-containing compounds which may be added to the slurry composition include, for example, nitrogen oxides, monoethanolamine, diethanolamine, triethanolamine, diethylene glycol amine, N-ethylhexanitrogen. It mixes the beta. These non-polymeric nitrogen-containing compounds may be present in the tanning composition at a concentration of from about 5% by weight to about 4% by weight, and, if any, 'usually about 〇.〇1% by weight based on the total weight of the slurry. Up to about 3% by weight of the preferred non-polymeric nitrogen-containing compound is an alkanolamine, preferably monoethanolamine. A preferred amount is from 0.5% to 2.5%. The CMP process described above may be followed by a grinding step. After 12 201133712 of the grinding step, if completed, according to the method of the present invention, the back side/carrier of the base wafer is disposed such that the back side of the base wafer is often placed face down on the polishing pad, and the polishing pad is not moved. Attached to the rotary platen of the CMP polisher. In this manner, the back side of the base wafer to be thrown and planarized is brought into contact with the polishing pad. Maintaining the base wafer/carrier with a wafer carrier system or polishing head and applying downward pressure to the backside/carrier of the base wafer during CMP processing while rotating the platen and the substrate . Applying (usually continuously) the polishing composition (first CMP slurry) to the mat during the (:1^1) treatment, passing the mat or between the mat and the wafer to cause the The material on the back side of the base wafer (eg, 'dream wafer') is removed. According to the present invention, the method of using the first CMP slurry can be performed at a force of 7 psi or less at a rate of 5,000 per knife hour. Polishing the first base wafer at a rate of angstroms. The 35 paste is preferably selected to polish the base wafer material at a higher rate than the metal via (eg, in the case of a germanium wafer) or to Flattening. In general, the selectivity of the slurry to oxidized zebra relative to copper is greater than 2 〇: i. The pH of the slag is advantageously above 9, and often above 1 〇. In an embodiment, the pH is between 1〇〇1 and 1〇49. In a particular embodiment, the pH is between 1〇5 and 115. In another embodiment, the ph The system is between 11.6 and η. In another embodiment, the lanthanide is between the old and the 13. The preferred ρ Η is between 11 and 12 'better Between 11.4 and 12. Using a pH-adjusting agent to improve the stability of the polishing composition improves the integrity of the use or meets the requirements of a variety of different specifications. Regarding the polishing composition that can be used to reduce the polishing composition of the present invention. The adjusting agent can be used as nitrogen chloride 13 201133712 acid, nitric acid, sulfuric acid, gaseous acetic acid, tartaric acid, succinic acid, citric acid, frequency acid, malonic acid, various fatty acids, and various polycarboxylic acids. In regard to the ruthenium adjusting agent which can be used for the purpose of increasing the pH, potassium hydroxide, sodium hydroxide, ammonia, tetramethylammonium hydroxide, hydrazine hydroxide, hexahydropyridine, polyethyleneimine, etc. can be used. The platen and head speed, as well as the downward force, are important factors. The graph shows the results of three different pressures and platen/head speed conditions used for polishing. Figure 1 shows the downward force at 1.5 psi. , i2 〇 rpm platen speed, 112 rpm head speed formed by the contour of the through hole, the through hole protrudes 5.7 to 6.3 microns above the base, and the oxidized tail slag protrudes 4 to 4.3 microns above the base (Y-axis Single micron incremental representation; X axis 4 〇 micron increments.) Figure 2 shows the profile of the through hole formed at 6 psi downward force, 35 rpm platen speed, 27 rpm head speed, and the through hole protrudes above the base by 6.3 μm. The tailings extend beyond the base by 3.3 to 35 microns (the γ-axis is expressed in single micron increments; the χ·axis is expressed in 4 〇 micron increments). Figure 3 shows the 6 psi downward force, 12 rpm platen speed, The profile of the through hole formed at 112rpni head speed, the through hole protrudes to 6 μm above the base, and the oxidized tailings slag extends to the top of the through hole, and the through hole failure is observed (the ¥_ axis is expressed in 2 micron increments; The _axis is expressed in 6 〇 micron increments). The polished enamel also has a considerable influence on the Si tail extension and the through hole protruding geometry. Utilizing Suba 6 〇〇 mat (hard), 6 4 psi (45 gram / cm) downward force, each independently about 8 〇 and 15 〇 E flow (Y-axis expressed in 8.5 micron increments; χ The _axis is expressed in increments of 25·6 microns. The 压-axis is expressed in 24 micron increments. The platen and head speed are polished using the 14 201133712 DP574 slurry. The through hole formed in the region having a single protruding through hole has a thick cerium oxide tail slag, and a relatively large portion with respect to the through hole is thicker than the through hole itself. In the region where a large number of through holes exist, the tail protrudes to almost 90% of the height of the through hole. Suba mats with a hardness greater than 90 Shore A are not recommended. An IC1 mattress with a 58 Shore D hardness is not recommended. The iC1000 series mats with a hardness of 60 to 65 Shore D are not recommended. However, it is highly recommended to use tweezers with a hardness of 5 〇 to 66 Shore A.

A mat with moderate softness', such as the NP2800 mat, 90 Shore A or 45 Shore D, provides a medium result, i.e., the tail slag extends more than half the height of the through hole. A Subo mat with a 78 Sh〇re A hardness is acceptable. Preferred are p〇Htex (61 Sh〇re A) and p〇retex (68 A). Furthermore, the selected polishing pad is recommended to have a high compression ratio, for example, up to 20% by volume. Use Politex mats (soft, 6〇 to 65 shore A), 6.4 pSi (450 g/cm3) downward force, each with nearly 2 rpm platen/head speed, 200 ml/min slurry flow by Dp574 The slurry polishes the wafer to provide a well-defined through-hole with significantly reduced height and thickness of the tailings, wherein when exposed from the back side of the wafer, the exposed metal through-holes appear behind the road to the top of the through-hole About half. Similar results were obtained even in areas where the through holes were densely packed. 15 201133712 The DP574 slurry has the composition of the following composition DP574 Syton HT-50 Si02* wt% 8.2 monoethanolamine wt% 0.34 ethylenediamine wt% 0.66 ethylenediaminetetraacetic acid wt% 0.02 deionized water wt% remainder* Syton HT-50 Si02 is a cerium oxide abrasive available from Dup〇nt Ak Products Nanomaterials, Inc., Tan Bi Valley, Arizona. Figure 4 shows the pressure using DP574 slurry, Suba 6(R) mat (hard), 64 psi (450 g/cm3) downward force, each independently about 8 rpm and 15 〇 ml/rnin slurry flow. The through hole formed by the disk and the head speed. The tailings are very thick and less than one third of the through holes are exposed metal. This can be compared to the through-holes shown in Figure 5, where SRS3 slurry, c2-c6 extended diamine is used, for example, (about 3.6% ethylenediamine), p〇litex mat (about 61 Shore A), 6.4 psi. (450 g/cm3) downward force, respective head/platen speed of about 2 rpm, 200 ml/min formed through holes with a very thin tail' and almost two-thirds of the through holes are exposed The metal that came out. The SRS3 slurry has the following composition: Composition SRS3

Syton HT-50 Si02* wt% 4.114007 Monoethanolamine wt% 0.174809 Ethylenediamine wt% 0-328634 Ethylenediaminetetraacetic acid weight 0/〇 deionized water wt% 0.010273 Remaining part 16 201133712 ♦Syton HT-50 Si02 is self-contained Nanxun catches ω ^ DuP〇ntAir from Arizona' Tanba Valley

Pr_CtS Nan〇materials Co., Ltd. obtained a dilute hair abrasive. The CMP process of the present invention is carried out by the higher downward force of the CMp implement. In a specific embodiment, the downward force is at least - in which the shot is specifically performed, the downward force being at least ^ (four) and 6 pS1, respectively. In other specific implementations! The downward force is between 4 and 4 to 20 PS1 '6 to 16 psi and 8 to 12 (four). Having a high downward force and a high speed may break the projection. Lower the downward force, resulting in a lower breaking amount but a thicker tail. With low speed and $ down to get the best available copper production and minimum _ tail. There is a specific implementation, the CMp method of this (4) is carried out by the lower platen speed of the (4) machine, for example, the platen speed in the range of 3 〇 S 〇〇 〇〇 rpm, for example, 30_ to 8 〇, More preferably 18 talks to 60 rpm (head speed should be in a similar range combination). There is a specific implementation that uses a softer tweezer, such as a P〇lltex mat, rather than a harder mat, such as an IC1010 mat. In one embodiment, the base wafer is a germanium wafer. One of the base wafers of the present invention has both a front side and a back side and the front side has an integrated circuit disposed thereon. The base wafer includes at least one conductive via including a conductive metal, and the at least one conductive via extends at least partially through the base wafer from the front of the base wafer. Preferably, there may be at least a consistent aperture for each of the replicated integrated circuit wafers on the wafer. The conductive metal of the at least one conductive via can generally be any electrically conductive 17 201133712 metal at ambient temperature. Conductive metals, which are not solids (e.g., under the conditions of temperature and pressure, the material of the pores: ruthenium), are excluded from the conductive vias that can be used in the present invention. Conductive Gold Isoelectrically, in a specific embodiment, the conductive metal has a ramp. In another embodiment, the $ is selected from the group consisting of copper and crane. In the method of launching the moon, the front side of the base wafer is fixed to a carrier. The carrier can be any material that can be processed in a subsequent CMP (as described below for the suitable wafer of the base wafer. Suitable Carrier material: but not limited to steel, glass and a variety of different polymers, such as olefins, polypropylene and poly(ethylene). In a specific embodiment of the method of the invention, the base crystal having an integrated circuit thereon Fixing the front side of the circle to the carrier can be accomplished in any manner known in the art. One example is to temporarily bond the front side of the base wafer to the carrier using a suitable adhesive while on the back of the base wafer. CMP processing and/or grinding is performed on the side. The base wafer is fixed on the carrier to provide a base wafer/carrier in a sandwich structure and the side of the base wafer (four) is an outer surface. The CMP process may or may not be performed before the CMP process. A grinding step of removing a substantial amount of material from the back side of the first base wafer is performed on the base wafer/carrier to planarize the back side of the base wafer. Any grinding method known in the art is performed. Available. In the specific embodiment, The back side of the base wafer is not subjected to a grinding step prior to mechanical polishing of the back side of the base wafer. In another embodiment, the base wafer is chemically polished prior to polishing the back side of the base wafer The back side is subjected to a grinding step. Next, after the grinding step, if completed, the back side/carrier of the base wafer is set according to the method of the present invention, and the boiled side of the base wafer is often facing downward. On the polishing pad, the polishing pad is immovably attached to the CMP polishing machine (four) rotary platen. In this way, the back side of the base wafer to be polished and planarized is brought into contact with the polishing pad. A polishing head holds the base wafer/carrier in position and applies downward pressure to the backside/carrier of the base wafer during CMp processing while rotating the platen and the substrate. During the CMP process Applying (usually continuously) the polishing composition (first CMp slurry) to the mat, passing the mat or between the mat and the wafer to cause the base wafer (eg, tantalum wafer) Back side material removal" the CMP slurry Preferably, the base wafer material (eg, germanium in the germanium wafer case) is polished or planarized at a higher rate than the metal via. The first base crystal is then applied after the CMP process described above. The round back side is thinned and planarized, and then the carrier can typically be removed and the resulting thinner base wafer can be used when exposing the through-substrate vias used to assemble the stacked integrated circuit wafers. After the planarization and thinning of the present invention are performed on the base wafer, the wafer is cut or diced to separate individual integrated circuit wafers each of which is replicated many times on the surface of the base wafer. Wafers often contain vias that allow individual integrated circuit wafers to be interconnected with other similar integrated circuit wafers or circuitd wafers from disparate base wafers and wafer processing. This forms two or more by one or more. A 3-D stack of integrated circuit wafers fabricated on a multi-base wafer. As explained above, the present invention is a method of fabricating a base wafer for constructing a package containing two or more integrated circuit chips, 201133712 at least one of the integrated circuit chips The base wafer is a stacked device when the integrated circuit wafer is assembled. The basic form of the method defines the planarization of the back side of the base wafer using chemical mechanical planarization (CMP) by a high base wafer material (e.g., germanium) removal rate. The method contemplates the use of a first CMP slurry comprising: a hydrazine liquid carrier; 2) a C2_C6 organic diamine; 3) an abrasive; and 4) at least one metal integrator. The liquid carrier present in the compositions utilized in the process of the present invention can be any liquid under conditions of (4) which have properties suitable for use in CMP slurries. Suitable liquid carriers are those which dissolve most or all of the components other than the abrasive and provide a more stable dispersion of the abrasive. Suitable liquid carriers include, but are not limited to, water and mixtures of water and organic compounds that are soluble or dispersible in water. A variety of different organic solvents as explained below can be used alone or in combination with water as a liquid carrier. The C2_ce organic diamine can be any organic diamine containing carbon, nitrogen and hydrogen atoms and having between (a) carbon atoms. In one embodiment, the organic diamine is one having two amine groups on the carbon atom of the adjacent, such as, for example, ethylenediamine or i,2-diaminopropane. In a preferred embodiment, the diamine is ethylene diamine. At least one metal chelating agent is present in the CMp slurry used in the CMP treatment of the process according to the invention. Suitable chelating agents for addition to the slurry composition include, but are not limited to, ethylenediaminetetraacetic acid, N-hydroxyethylethylamine triacetate, cyanotriacetic acid, diethylenetriaminepentaacetic acid, ethanol diganate Amine vinegar, amino acetic acid, N-tris(methyl)methylglycine, citric acid, 2'3 butanone monohydrazine (dimethylglycodone oxime lanthanum carbonate and mixtures thereof. 20 201133712 The chelating agent may be present in the slurry composition at a concentration of from about 0.03 wt% to about 10 wt%, based on the total weight of the slurry. In one embodiment, the chelating agent is based on the total weight of the paste. It is present at a concentration of from about 1% by weight to about 5% by weight. In another embodiment, the chelating agent is present in an amount of from about 5% by weight to about 4% by weight based on the total weight of the slurry. In another embodiment, the chelating agent is present at a concentration of from about 4% by weight to about 0.1% by weight. Standard (unmodified) abrasives and surface modified abrasives when used together Both can be used in the present invention. Suitable unmodified abrasives include, but are not limited to, oxygen Dreaming, oxidizing, oxidizing, oxidizing, cerium oxide, cerium oxide and their co-formed products, and mixtures thereof. Treatment of unmodified abrasives using inorganic or organometallic compounds (eg, oxidation) The surface-modified abrasive can also be used in the present invention. The inorganic compounds suitable for upgrading include cyanic acid, sodium citrate and potassium citrate. The organic compounds suitable for upgrading include acetic acid, formic acid and propionate. Suitable abrasives include, but are not limited to, colloidal products, fuming products, and mixtures thereof, which are modified by the following examples - some of the specified examples are the side acid to modify the oxidation dream to obtain a modified surface. The oxygen is cut and the fossil is modified by using the acid or sodium acid to obtain the oxidative dream of the surface of the salt. The oxygen-cut and surface-modified oxide stone is used as the abrasive material. Compared with .A ^, silicone rubber, fumed stone and other oxygen-cut dispersions; surface-modified dream gel. Preferred oxygen cutting is a dream gel or in most embodiments, the abrasive The total weight of the aggregate 21 201133712 A concentration of from about 0.001% by weight to about 30% by weight is present in the slurry. In one embodiment, the abrasive is from about 5% by weight to about 20% by weight based on the total weight of the slurry. /浓度 concentration exists in another embodiment, the abrasive is present in a concentration of from about 1% by weight to about 1% by weight based on the total weight of the slurry, and in yet another embodiment, The abrasive is present at a concentration of from about 1% to about 5% by weight. Other chemicals that can be added to the CMP slurry composition include, by way of example, other oxidizing agents, water-miscible solvents, surfactants. , modifiers, acids, corrosion inhibitors, fluorochemicals, chelating agents, non-polymeric nitrogen-containing compounds and salts. Suitable water-miscible solvents that can be added to the slurry composition include, for example, Ethyl acetate, methanol, ethanol, propanol, isopropanol, butanol, glycerol, ethylene glycol, and propylene glycol, and mixtures thereof. In a particular embodiment, the water-miscible solvents may be present in the (iv) composition at a concentration of from about 5% by weight to about 4% by weight, and in another embodiment about Μ by weight. /. To a concentration of about 2% by weight' and in still another embodiment about 0.5% by weight. /. a concentration of up to about 1% by weight; these Chiang w values are each based on the total weight of the slurry. A preferred type of water-miscible solvent, alcohol, butanol and glycerin may be added to the slurry. Suitable surfactants include, for example, 'a wide variety of nonionics known to those skilled in the art. Any of a subtype, a cationic or an amphoteric surfactant. In the embodiment, the surfactant compound may be present in the slurry composition at a concentration of from about 0% by weight to about 1% by weight, based on about 1 weight, in a specific embodiment, 22 201133712, about 0.0005 weight. a concentration of from about 1% by weight to about 1% by weight, and in yet another embodiment (a concentration of UHH by weight to about G.5% by weight; these weight % values are each based on the total weight of the slurry. The preferred type of active agent is nonionic, anionic or a mixture thereof and is preferably a total of M_10 ppm mM 1000 ppmm^nu_ subtype surfactant of the slurry. The pH-adjusting agent is used to improve the stability of the polishing composition. Sexuality, change the requirements of different specifications. Regarding the pH-adjusting agent capable of using pH, it is possible to use hydrogen tartaric acid, succinic acid, citric acid, safety at the time of use or a variety of gases to reduce the polishing composition of the present invention. , nitric acid, sulfuric acid, acetic acid, malic acid, malonic acid, a variety of different fatty acids, a variety of different polycarboxylic acids. On the other hand, regarding the 2pH adjuster that can be used for the purpose of increasing the pH, nitrogen oxidation can be used to remove hydrogen. Sodium oxide Ammonia, tetramethyl sulphate, hydrazine hydroxide, hexahydropyridine, polyethyleneimine, etc. In one embodiment, a suitable laboratory slurry PH, for example, from about 7 to about ^. In a particular embodiment, a suitable slurry has a pH of from about 8 to about 1 Torr. In another embodiment, the PH system is between 10.01 and 1 〇 49. In one embodiment, the PH system is between 1().5 and u.5n In another embodiment, the pH system is between 11.6 and 13. It may be added to the suitable acid compound of the slurry composition (instead of or in addition to the pH value mentioned above). In addition to adjusting acids, including, but not limited to, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, money, caprylic acid, citric acid, lactic acid, nitrogenic acid, tartaric acid, squaric acid, sulfuric acid, hydrofluoric acid Acid, malic acid, tartaric acid, glucosamine, citric acid, phthalic acid, pyrocatechin, pyrophoric age 23 201133712 Carboxylic acid, gallic acid, tannic acid and pots and mixtures thereof. These acid compounds can be about the pulp The total weight of the material is about 〇 詈. / 5 ^ ^ amount / ° to about 5% by weight of the concentration is present in the slurry composition. The phlegm-reducing inhibitor added to the slurry composition includes, for example, 1,2,4-bind, benzotriazine, 6-methyl, _1^ +yy, d-butyl diazine, tolyl a triazine derivative, 1-(2,3-dicarboxypropyl)benzoxanthene and a branched alkylphenol-substituted benzoindole compound. "This is a useful commercial corrosion inhibition." Agent includes

MafolSMODl ' Iconol TDA ο η τ , 〇 OHDA-9 and lcon〇i TDA_6 (all available from BASF Ltd. in Floham Park, New Jersey), and Heart (10) MI 110 (available from California 'Camarillo (10) Limited obtained). In a specific embodiment, the corrosion inhibitor is a phenolic compound, and in another embodiment the compound is present in an amount between Q(8)i% by weight (i〇ppm) and 5% by weight. . In one embodiment, the corrosion inhibitor may be present in the slurry at a concentration of from about 0 ppm to about 4 ppm by weight - in another embodiment from about 1 〇 ppln to about 4 〇〇〇 ppm in another In particular embodiments, from about 50 ppm to about 200 ppm, and in yet another embodiment from about 50 ppm to about 5 ppm, all based on the total weight of the slurry. In one embodiment, the corrosion inhibitor is present in an amount between 0.0005 weight percent (5 ppm) and weight percent (1 ppm). When a carboxylic acid is added, the corrosion inhibiting property of the slurry composition can also be imparted. To further improve the selectivity of the removal of a particular metal relative to the dielectric and/or base wafer material during CMP, fluorochemical 24 201133712 may be added to the slurry composition, if necessary. Suitable fluorine-containing compounds include, for example, hydrogen fluoride, perfluoric acid, alkali metal fluoride salts, alkaline earth metal fluoride salts, ammonium fluoride, tetramethylammonium fluoride, ammonium difluoride, and ethylene difluoride. Ammonium, trifluorodiethylenetriammonium and mixtures thereof. In one embodiment, the fluorochemical may be present in the feedstock composition at a concentration of from about 5% by weight to about 5% by weight, and in another embodiment preferably from about 6.55% by weight to about 5% by weight. In yet another embodiment, from about 0.5% to about 2% by weight, all based on the total weight of the slurry. A suitable fluorine-containing compound is ammonium fluoride. Suitable non-polymeric nitrogen-containing compounds (amines, hydroxides, etc.) which may be added to the slurry composition include, for example, ammonium hydroxide, monoethanolamine, diethanolamine, triethanolamine, diethylene glycol Amine, N-hydroxyethyl hexahydropyridine and mixtures thereof. These non-polymeric nitrogen-containing compounds may be present in the slurry composition at a concentration of from about 5% by weight to about 4% by weight, and, if any, 'usually about 〇.〇1% by weight based on the total weight of the slurry. It is present in an amount of up to about 3% by weight. A preferred non-polymer nitrogen-containing compound is monoethanolamine. Still other chemicals which can be added to the composition of the composition are biological agents such as bactericides, biocides and fungicides, especially if the pH is between about 6 and 9. Suitable fungicides include, but are not limited to, 12_benzisothiazolin-3-one; 2-(hydroxymethyl)aminoethanol; 1,3_di-methyl-5,5-didecyl Urea urea; 1-hydroxymethyl-5,5-dimethylacetal gland; % iodo-2-propynyl-butylcarbamate; glutaraldehyde; 12-dibromo-2,4 • dicyanobutane; 5-chloro-2-indolyl-4-isothiazolin-3-one; 2-methyl-4-isothiazolin-3-one and mixtures thereof. Preferred bactericides are sputum and stupid and dissident saliva. When present, the biocide is typically present at a concentration of from about 25 201133712 0.001 weight percent per gram to about 5% by weight based on the total weight of the slurry. The CMP method utilized in the present invention uses the aforementioned composition (as disclosed above) for chemical mechanical planarization of the backside of the base wafer (e.g., germanium wafer) during processing through the base wafer. In one embodiment, the base wafer is a germanium wafer. In one embodiment, the present invention is a method of fabricating a base wafer for constructing a package including at least two integrated circuit wafers, at least one of which is derived from the base Wafer, the method comprising: a) providing a first base wafer having a front side and a back side, wherein the front side comprises an integrated circuit disposed on the first base wafer and wherein the base wafer comprises at least one conductive a through hole, the at least one conductive via comprises a conductive metal and extends at least partially through the base wafer from the base wafer; b) fixing a front side of the base wafer having the integrated circuit thereon to the carrier; c) The back side of the base wafer is contacted with a polishing pad and a first CMP slurry, the first CMP slurry comprising: 1) a liquid carrier; 2) a C2-C6 organic diamine; 3) an abrasive; and 4) At least one metal chelating agent, and d) polishing the back side of the base wafer until exposed or further exposed at least one conductive via hole' wherein it is used at a rate of at least 10,000 angstroms per minute at a downward force of 6 psi The first CMP slurry polishes the first base 26 201133712 Round. In another embodiment, the present invention is a method for preparing a base wafer, which is used for constructing a package containing at least two integrated circuit wafers. The isolithic circuit crystal Μ $ $ & W at least - from the base wafer,

The method includes: a) providing a first-based wafer having a front side and a back side, wherein the front side includes an integrated circuit disposed on the first base wafer and wherein the base wafer includes at least a conductive via, the at least a conductive via comprising a conductive metal and extending at least partially through the base wafer from a front surface of the base wafer; b) contacting a back side of the base wafer with a polishing pad and a __cMp slurry, the first A CMP slurry comprises: 1) a liquid carrier; 2) a C2-C6 organic diamine; 3) an abrasive, the abrasive being suspended in the slurry, the grinding being fixed to the polishing crucible, or both; 4) at least one metal nucleating agent, and Ο polishing the back side of the base wafer until exposed or further exposed at least - conductive through hole 'at at least 1 每, _ angstroms per minute at a downward force of 6 psi The wafer is polished using the first CMp reject at a rate. The invention is further illustrated by the following examples. EXAMPLES Symbols and Definitions: 27 201133712 1. CMP is chemical mechanical planarization = chemical mechanical polishing 2. Λ is angstrom, unit of length 3. A / min is the polishing rate expressed in angstroms per minute 4. psi is per square metre Fragment 5· BP is the back pressure expressed in psi 6. PS is the platen rotation speed of the polishing machine, expressed in rpm (revolutions per minute) 7. SF is the slurry flow rate expressed in ml/min 8. CS The speed of the carrier is 9. DF is the downward force expressed in pSi 10. Min is minute 11. ml is ml 12. mV is millivolt 13. NA means that the data cannot be obtained 14. rpm is 15 revolutions per minute. The dust disk is a rotating table on which the polishing is performed. The head is a rotating device that holds the wafer thereon and is moved in contact with the disk for polishing. Unless otherwise specified, otherwise the concentration of all components is % by weight. Implementation Correction 1 A point-of-use slurry having the following composition was produced: 1) Silicone 4.1140% by weight 28 201133712 2) EDTA 〇·1130% by weight 3) Monoethanolamine 1.9229% by weight 4) Ethylenediamine 3.6150 〇/0 5) Deionization Water Remaining Portion (4) The pH of the slurry is about η·6β. The slurry is used to polish the back side of the germanium containing wafer using the general method described above. Polishing conditions of 6 psi downward force, 12 〇 rPm platen speed, 112 rpm head speed and 200 ml/min slurry flow on R〇hmandHaas Pohtex mats at a higher rate of 21'593 angstroms per minute Remove the shreds from the stone-containing wafer. (b) polishing the back side of the ruthenium containing wafer having copper vias using the paste using the general method described above. A 6 psi downward force, a 35 rpm platen speed, and a 27 rpm head speed polishing condition resulted in a copper through-hole protrusion length of approximately 65 microns. The dovetail appears upwardly along the exposed through-hole to an extent of about 3 to 3.5 microns. Due to this amount of tailings slag, there is still a copper through hole length of about 3 to 3.5 microns that can be exposed. This high downward force case provides better results than the case of the low down force in Example 2. Example 2 The same slurry as in Example 1 was used. The forged side of the copper-filled wafer is polished using the forging material using the general method described above. A polishing condition of 15 psi downward force, 120 rpm platen speed and 112 rpm head speed' resulted in a copper through hole protrusion length of approximately 6.5 microns. The tail of the Shi Xi appeared up to about 4 microns along the exposed through hole. Due to this amount of tailings slag, there is still a steel through hole length of about 2 to 2.5 microns that can be exposed. 29 201133712 This low downward force case provides worse results than the case of the high down force in Example 1. Example 3 A point-of-use slurry having the following composition was produced: 1) Silicone 4.1140% by weight 2) EDTA 0.0103% by weight 3) Monoethanolamine 0.1748% by weight 4) Ethylenediamine 0.3286% by weight 5) Similar slurry of deionized water remaining It is known as DP574. The pH of the slurry is about 丨2 ^ The back side of the ruthenium containing wafer is polished using the slurry using the general method described above. Polishing conditions of 6 psi downward force, 12 rpm platen speed, 112 head speed and 200 ml/min slurry flow on a Rohm and Haas Politex mat at a lower rate of 14,839 angstroms per minute The germanium containing wafer removes the dream. Example 4 A number of polishing experiments were carried out using a slurry similar or identical to the previous examples, in which the effects of mechanical parameters were investigated. See Figure for forming a through hole at 1.5 psi downward force, 12 rpm platen speed, 112 rpm head β卩 speed, and the through hole extends above the base to the knive to 6.3 μm. The base is 4 to 4 microns. See Figure 2 'It shows no downward force at 6 psi, 35 plate speed = 201133712 degrees 27 rpm head speed to form a through hole, the through hole protrudes above the base 6.3 microns, the slag slag hole penetration Out to 3 3 to 3 5 microns above the base. Referring to Figure 3, at 6 psi downward force, 12 rpm platen speed, 112 rpm head speed to form a through hole, the through hole extends 6 microns above the base, and the oxidized stone extends to the top of the through hole . In this example, a moderate downward force and a high platen/head speed were used, but a through hole failure was observed. See Figure 4' which shows the use of DP574 slurry, Suba 600 mat (hard), 6.4 The downward force of psi (450 g/cm3), the platen and head speed of about 8 rpm, and the through-hole formed by the 15 〇mi/min reject flow. See Figure 5, which shows the downward force using SRS3 slurry (about 3 6% ethylenediamine), politex mat (about 61 Sh〇re A), 6 4 (four) (45 g/cm3), each about 20 The rpm head/platen speed, the through hole formed by 2〇〇ml/min. The shape of the through hole described in the reverse figure and the embodiment shows a long hole formed by a narrow tail slag which extends less than about half of the path along the through hole and may only be obtained at a low pressure disk and head speed. It uses a soft compression pad and aggressive CMP slurry chemistry to remove yttrium oxide without damaging the via. The resulting via may extend vertically from a plane formed by the backside of the wafer to a length of from 5 microns to about 100 microseconds, but is often from 6 microns to about 30 microns in length. Once ready, the wafer can be bonded to other wafers into a stacked device containing two or more stacked wafers. These examples are intended to illustrate and not to limit the invention. 31 201133712 [Simple diagram of the diagram] Figure 1. The through hole formed at 1.5 psi downward force, 12 rpm platen speed, 112 rpm head speed, and the through hole protrudes 5.7 to 6.3 μm above the base. The cerium oxide tail slag protrudes 4 to 43 microns above the base (Comparative Example). Figure 2. The through hole formed at a 6 psi downward force, a 35 rpm platen speed, and a 27 rpm head speed. The through hole protrudes 63 microns above the base, and the slag slag hole extends above the base. 3 · 3 to 3 5 μm (present invention). Figure 3. At 6 psi downward force, 12 rpm platen speed, 112 rpm head speed formed through the through hole, the through hole protrudes above the base 6 μm. The oxidized tailings slag extends to the top of the through hole. Perforation failure was observed (comparative example). Figure 4, using DP574 slurry, Suba 600 mat (hard), 64 4 psi (450 g/cm3) downward force, respective 8 rpm platen and head speed, 150 ml/min slurry flow The formed through hole (present invention). Figure 5 'Using SRS3 slurry (about 3,6% ethylenediamine), p〇litex mat (about 61 Shore A), 6.4 psi (450 g/cm3) of downward force, each about 20 rpm head / platen speed, 200 ml / min through the formation of the through hole (this is clearly). 32

Claims (1)

201133712 VII. Patent application scope: 1. A method for preparing a base wafer, which is used for an assembly of an I-stack circuit chip, at least one of which is derived from the base wafer, and the method includes A) of the laminated body circuit wafer is provided with a front side and a back side of a ^ a £ a - ^ . a ^ day circle, wherein the front side package is again placed on the first base wafer of the integrated circuit # M And the base wafer includes at least one conductive via hole, the at least one conductive via hole comprising a conductive metal and extending at least a front surface of the circle; The base crystal:) contacting the back side of the base wafer with the polishing crucible and the CMp slurry, the rotation of the head and the rotation of the dice causing a slurry between the wafer and the polishing pad Grinding, and C) polishing the back side of the base wafer to the plague Lingshan bucket, and the side of the circle is exposed to expose or further expose at least the conductive through hole extending from the back side of the wafer 'where a downward force of at least 4 Psi is applied during polishing, wherein the polished crucible has 45 The hardness of sh〇reA to about 85 shore A, wherein the platen and head speed are each independently from 18 rpm to 60 rpm, and wherein the polymer comprises a liquid carrier at 0.2 weight/. And 6% by weight of a C2_C6 organic diamine 'abrasive and at least one metal chelating agent. 2. A method according to the scope of application of the invention, wherein the slurry comprises a liquid carrier, between 0.2% and 6% by weight of a C2_C4 organic diamine, and an oxidation between 2% and 1% by weight. Dream and at least - metal integrator. 33 201133712 3. The scope of the patent application is in the range of from 0.01 to about 4% by weight to the method wherein the slurry additionally comprises a non-polymeric nitrogen-containing compound. Wherein the non-polymer contains nitrogen nitride. 4. The method of claim 3 is an alkanolamine. 5. The method of claim </RTI> wherein the slurry comprises from 1 weight percent to about 4 weight percent of the c2-C6 organic diamine. &amp; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> the polishing pad has a hardness value between 45 Shore A and about 7G ShQre A and the polishing pad has a compression ratio between 8 vol% and 20 vol%. 7. The method of claim IA, wherein the downward force is 6 PS1 to 10 psi' and the wafer material removal rate is higher than 12 per minute under a downward force of 6 〇〇 〇埃. 8. The method of claim 2, wherein the at least one conductive via extends perpendicularly from a plane formed by the back side of the wafer by 6 microns to about 3 microns. 9. A method of preparing a base wafer, The base wafer is used to construct a package comprising at least two integrated circuit chips, at least one of which is from the base wafer. The method comprises: 34 201133712 a) provided with front side and back side The first base wafer, wherein the front side comprises an integrated circuit disposed on the first base wafer and wherein the base wafer comprises at least one conductive via hole, the at least one conductive via hole comprises a conductive metal and at least partially penetrates The base wafer protrudes from the front surface of the base wafer; b) the front side of the base wafer having the integrated circuit thereon is fixed to the receiving member; c) the back side of the base wafer and the polishing pad and the first - CMp (iv) contact, the first CMP polymer comprising: 1) a liquid carrier; 2) a C2-C6 organic diamine; 3) an abrasive; and 4) at least one metal chelating agent, and or further exposed to d) polishing The back side of the base wafer is exposed until 6 p The downward force of si is used to polish one of the first CMP pastes with a conductive via, wherein the first base wafer is at a rate of at least 10,000 angstroms. 10. The method of claim 9, wherein the base wafer W and the conductive metal are selected from the group consisting of copper and crane. 11. The scope of the patent application is ethylenediamine. The method of item 10, wherein the (32-(6 organic diamine 12. method of claim 10, wherein the c2-c6 organic diamine 35 201133712 is so far) is present in an amount of 1 weight percent. For example, the patent scope is 第ethylenediaminetetraacetic acid. The metal nutrient agent is 14. The alcoholic amine of the 12th item of the patent application, the Yuanzhong material additionally contains an alcoholic amine, wherein the charge The Qiu system is used to polish the first base wafer with a slurry having a downward force of 0 or less, and 6 psi and a mother knife of at least 16,0 angstroms. The method of preparing a base wafer for constructing an assembly comprising at least two integrated circuit wafers, wherein at least one of the integrated circuit wafers is from the base wafer The method includes: providing a first base wafer having a front side and a back side, wherein the front side package U (four) 1 base wafer ± integrated circuit and the base wafer includes at least a conductive through hole, the at least one conductive The via comprises a conductive metal and at least partially passes through the base wafer from the Extending the front side of the wafer; b) contacting the back side of the base wafer with the polishing crucible and the CMp crack, and polishing the back side of the base wafer until at least one conductive via is exposed or further exposed, wherein A downward force of at least 4 psi is applied during polishing, wherein the polishing crucible has a hardness of from 45 Shore A to about (four) one, wherein the platen and head speed are each independently from 18 叩 111 to 6 〇卬 111. 16. The method of claim 15, wherein the first base wafer is a 36 201133712 silicon wafer, and wherein the conductive metal is selected from the group consisting of copper and tungsten. 17. The method of claim 15 wherein the polishing pad has a hardness value between 45 Shore A and about 70 Shore A and the polishing pad has a compression ratio between 8% and 20%. 37