Patent Publication Number: US-2023163065-A1

Title: Stack type semiconductor device and method of manufacturing the same

Description:
CROSS-REFERENCES TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. § 119(a) to Korean application number 10-2021-0164534, filed on Nov. 25, 2021, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     Various embodiments generally relate to a semiconductor integrated circuit technology, more particularly, to a stack type semiconductor device capable of testing a bonding error after a hybrid bonding process, and a method of manufacturing the stack type semiconductor device. 
     2. Related Art 
     As a high-integrated circuit device is continuously developed, a pitch size of the integrated circuit device may be decreased. Thus, a packaging technology of the high-integrated circuit device may also be developed. The packaging technology may include a ball grid array (BGA), a chip scale package (CSP), a wafer level package (WLP), a three-dimensional package, a system in package (SIP), etc. 
     Currently, a three-dimensional stack type package may be proposed. The three-dimensional stack type packages may be formed by bonding wafers to each other and then sawing the bonded wafers to form the packages. The packaging process may be performed at a wafer unit so that fabrication processes may be reduced and the packages may each have a small size. 
     SUMMARY 
     In one embodiment, a stack type semiconductor device may include a stack wafer structure and a conductive path. The stack wafer structure may include a plurality of wafers that are hybrid-bonded to each other. Each of the wafers may include one or more semiconductor chips. The conductive path may include a plurality of vertical connection structures and one or more horizontal connection structures. The vertical connection structures may be formed through the stack wafer structure. The horizontal connection structures may be configured to connect the vertical connection structures. 
     In one embodiment, a stack type semiconductor device may include a first wafer, a second wafer, a conductive path, a transmitter, and a receiver. The first wafer and the second wafer may be bonded to each other via a plurality of bonding patterns, the plurality of bonding patterns including a plurality of layers. Each of the first and second wafers may include a one or more semiconductor chips. The conductive path may be configured to extend through the first and second wafers. The transmitter may be connected to a first end of the conductive path to receive a test voltage. The receiver may be connected to a second end of the conductive path to detect a current that is generated from the test voltage. 
     In one embodiment, according to a method of manufacturing a stack type semiconductor device, bonded wafers may be formed by hybrid-bonding a plurality of wafers. A test current may be provided to the bonded wafers by applying a test bias (voltage) to a conductive path through the bonded wafers, where an open circuit in the conductive path results in a test current of zero amperes. A bonding error of the bonded wafers may be determined by measuring the test current. The bonded wafers may be sawed into a plurality of semiconductor chips. Each of the semiconductor chips may then be packaged. 
     In one embodiment, a stack type semiconductor device may include a stack wafer structure including a plurality of connection structures. The plurality of wafers may be hybrid-bonded to each other. A plurality of connection structures may be in each of the plurality of wafers. The plurality of connection structures may form a conductive path for a test current, the conductive path interconnecting the plurality of wafers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of the subject matter of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a perspective view illustrating a stack type semiconductor device in accordance with example embodiments; 
         FIGS.  2 A and  2 B  are plan views illustrating an upper surface and a bottom surface of a wafer in a stack type semiconductor device in accordance with example embodiments; 
         FIG.  3    is a perspective view illustrating a plurality of bonded semiconductor chips in accordance with example embodiments; 
         FIG.  4 A  is a perspective view illustrating a stack type semiconductor device to which a face-to-face bonding process is applied in accordance with example embodiments; 
         FIG.  4 B  is a perspective view illustrating a stack type semiconductor device to which a back-to-back bonding process is applied in accordance with example embodiments; 
         FIG.  5 A  is a plan view illustrating a semiconductor chip of a first wafer in a stack type semiconductor device in accordance with example embodiments; 
         FIG.  5 B  is a plan view illustrating a semiconductor chip of a second wafer bonded to the semiconductor chip in  FIG.  5 A  by a face-to-face bonding process in accordance with example embodiments; 
         FIGS.  6 A and  6 B  are cross-sectional views illustrating a stack type semiconductor device in accordance with example embodiments; 
         FIG.  7    is a cross-sectional view illustrating a conductive path in a stack type semiconductor device in accordance with example embodiments; 
         FIGS.  8 A and  8 B  are plan views illustrating a transmitter and a receiver in a stack type semiconductor device in accordance with example embodiments; 
         FIG.  9    is an enlarged cross-sectional view illustrating a stack type semiconductor device bonded by a face-to-face bonding process in accordance with example embodiments; 
         FIG.  10    is an enlarged cross-sectional view illustrating a hybrid bonding pattern of a stack type semiconductor device in accordance with example embodiments; 
         FIG.  11    is an enlarged cross-sectional view illustrating a stack type semiconductor device including stacked four wafers in accordance with example embodiments; 
         FIG.  12    is an enlarged cross-sectional view illustrating a stack type semiconductor device including two wafers bonded by a face-to-face bonding process in accordance with example embodiments; 
         FIG.  13    is an enlarged cross-sectional view illustrating a stack type semiconductor device including four wafers bonded by various techniques in accordance with example embodiments; and 
         FIG.  14    is a flow chart illustrating a method of manufacturing a stack type semiconductor device in accordance with example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments of the present disclosure will be described in greater detail with reference to the accompanying drawings. The drawings are schematic illustrations of various embodiments (and intermediate structures). As such, variations from the configurations and shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, the described embodiments should not be construed as being limited to the particular configurations and shapes illustrated herein but may include deviations in configurations and shapes which do not depart from the spirit and scope of the present disclosure as defined in the appended claims. 
     The present disclosure describes various embodiments with reference to the provided illustrations. However, the present disclosure should not be construed as being limited to the disclosed embodiments. Although a few embodiments of the present disclosure will be shown and described, it will be appreciated by those of ordinary skill in the art that changes may be made to provide other embodiments without departing from the principles and spirit of the present disclosure. 
       FIG.  1    is a perspective view illustrating a stack type semiconductor device in accordance with example embodiments,  FIGS.  2 A and  2 B  are plan views illustrating an upper surface and a bottom surface of a wafer in a stack type semiconductor device in accordance with example embodiments and  FIG.  3    is a perspective view illustrating a plurality of bonded semiconductor chips in accordance with example embodiments. 
     Referring to  FIG.  1   , a stack type semiconductor device  100  may include a plurality of stacked wafers W 1 ˜Wn. Each of the wafers W 1 ˜Wn may include a plurality of semiconductor chips  10 . 
     Referring to  FIGS.  2 A and  2 B , the wafer W may include an upper surface W_F and a bottom surface W_B, the bottom surface W_B being on the opposite side of the upper surface W_F. For example, a device layer may be formed on the upper surface W_F of the wafer W. At least one bonding pattern may be formed on at least one of the upper surface W_F and the bottom surface W_B of the wafer W. The bonding pattern may be electrically connected to a through silicon via (TSV) that is formed through the wafer W. 
     As mentioned above, the TSV may be an electrode that is formed through the wafer W. The plurality of wafers W 1 ˜Wn may be stacked through a hybrid bonding process. The hybrid bonding process may be a technique of attaching the bonding patterns of the wafers W 1 ˜Wn. The bonding patterns may include a conductive material and an insulating material. The hybrid bonding process may be interpreted as a direct bonding interconnection process or a fusion boding process. 
     However, after wafers W 1 ˜Wn are stacked through the hybrid bonding process, a bonding failure, such as a wafer crack, a misalignment between the bonding patterns, etc., might not be detected, because there is no test process between the hybrid bonding process stage and the packaging test stage. Thus, a packaging process may be performed after the wafers are divided into bonded chips  10 - 1 ˜ 10 - 4 , as shown in  FIG.  3   , without said test process, resulting in the bonding failure remaining undiscovered. After the multi-chip package is completed through the packaging process, the packaging test may be performed on the multi-chip package. When an error is detected in the packaging test, it may be difficult to accurately determine which process resulted in the error. 
     According to example embodiments, the stack type semiconductor device  100  may provide a conductive path, extended by way of the bonded wafers, through which a test current may flow. Thus, the bonding failure may be monitored after the bonding process. 
     The bonded wafers or the bonded semiconductor chips may include a test pad region in which test pads may be arranged. The test pad region may include a conductive path configured to conduct a test current in vertical and horizontal directions. A test bias (voltage) may be applied to one end of the conductive path. The amount of the test current that flows through the conductive path may be detected at the other end of the conductive path to monitor problems, such as a bonding failure, a crack, etc. 
       FIG.  4 A  is a perspective view illustrating a stack type semiconductor device to which a face-to-face bonding process is applied in accordance with example embodiments, and  FIG.  4 B  is a perspective view illustrating a stack type semiconductor device to which a back-to-back bonding process is applied in accordance with example embodiments.  FIGS.  4 A and  4 B  may show only two wafers for conveniences of explanations. 
     Referring to  FIG.  4 A , an upper surface W_F of a first wafer W 1  may face an upper surface W_F of the second wafer W 2 . The first wafer W 1  may then be bonded to the second wafer W 2 . That is, the second wafer W 2 , which is flipped at an angle of about 180° based on a virtual reference line RL, may be bonded to the upper surface W_F of the first wafer W 1 . This bonding process in which the upper surfaces W_F of the first and second wafers W 1  and W 2  faces to each other may be referred to as a face-to-face bonding process. 
     Referring to  FIG.  4 B , a bottom surface W_B of the first wafer W 1  may face a bottom surface W_B of the second wafer W 2 . The first wafer W 1  may then be bonded to the second wafer W 2 . This bonding process in which the bottom surfaces W_B of the first and second wafers W 1  and W 2  face each other may be referred to as a back-to-back bonding process. 
     Alternatively, the upper surface W_F of the first wafer W 1  may be bonded to the bottom surface W_B of the second wafer W 2 . 
       FIG.  5 A  is a plan view illustrating a semiconductor chip of a first wafer in a stack type semiconductor device in accordance with example embodiments, and  FIG.  5 B  is a plan view illustrating a semiconductor chip of a second wafer bonded to the semiconductor chip in  FIG.  5 A  by a face-to-face bonding process in accordance with example embodiments. 
     Referring to  FIGS.  5 A and  5 B , the first wafer W 1  and the second wafer W 2  may be stacked with their upper surfaces facing each other. For example, a first semiconductor chip  10 - 1  of the first wafer W 1  and a second semiconductor chip  10 - 2  of the second wafer W 2  may face each other. When the first wafer W 1  and the second wafer W 2  have the same structure, the position of the first semiconductor chip  10 - 1  is different from that of the second semiconductor chip  10 - 2 . For example, the first semiconductor chip  10 - 1  and the second semiconductor chip  10 - 2  may be symmetrically arranged with respect to a center line CL of the first or second wafers W 1  or W 2 . 
     For example, the first and second semiconductor chips  10 - 1  and  10 - 2  may include a main region A 1  and an edge region A 2 . Semiconductor integrated circuits may be arranged in the main region A 1 . The edge region A 2  may be configured to surround the main region A 1 . At least one test pad may be arranged in the edge region A 2 . 
     In order to explain a connection between monitoring patterns in the face-to-face bonding process, the edge region A 2  may be divided into a left edge region A 2   l,  a right edge region A 2   r,  an up edge region A 2   u,  and a down edge region A 2   d.    
     The monitoring patterns MP may include left monitoring patterns MPl 1 ˜MPln in the left edge region A 2   l,  right monitoring patterns MPr 1 ˜MPrn in the right edge region A 2   r,  up monitoring patterns MPu 1 ˜MPum in the up edge region A 2   u,  and down monitoring patterns MPd 1 ˜MPdm in the down edge region A 2   d.    
     Each of the monitoring patterns MP may be a part of a vertical connection structure that is formed through the semiconductor chips  10 - 1  and  10 - 2 . For example, the monitoring pattern MP may be a bonding pattern or a pad electrode that is connected to the vertical connection structure in the edge region A 2 . Although not depicted in the drawings, a signal transmission pad may also be formed in the main region A 1 . 
     Further, the semiconductor chips  10 - 1  and  10 - 2  may include a connection pattern CP configured to connect the adjacent monitoring patterns MP with each other, thereby providing a horizontal conductive path. For example, the monitoring pattern MP may be connected to any one of the adjacent monitoring patterns through the connection pattern CP. In contrast, the monitoring pattern MP may be spaced apart from the remaining monitoring pattern. 
     For example, the second left monitoring pattern MPl 2  of the first and second semiconductor chips  10 - 1  and  10 - 2  may be connected to the adjacent first left monitoring pattern MPl 1  through the connection pattern CP. In contrast, the second left monitoring pattern MPl 2  may be electrically isolated from the third left monitoring pattern MPl 3 . Further, the fourth left monitoring pattern MPl 4  may be connected to the adjacent third left monitoring pattern MPl 3  through the connection pattern CP. In contrast, the fourth left monitoring pattern MPl 4  may be electrically isolated from the fifth left monitoring pattern MPl 5 . 
     The second right monitoring pattern MPr 2 , which may be eventually bonded to the second left monitoring pattern MPl 2 , may be electrically isolated from the adjacent first right monitoring pattern MPr 1 . In contrast, the second right monitoring pattern MPr 2  may be electrically connected to the third right monitoring pattern MPr 3  through the connection pattern CP. The fourth right monitoring pattern MPr 4 , which may be eventually bonded to the fourth left monitoring pattern MPl 4 , may be electrically isolated from the adjacent third right monitoring pattern MPr 3 . In contrast, the fourth right monitoring pattern MPr 4  may be electrically connected to the fifth right monitoring pattern MPr 5  through the connection pattern CP. 
       FIGS.  6 A and  6 B  are cross-sectional views illustrating a stack type semiconductor device in accordance with example embodiments, and  FIG.  7    is a cross-sectional view illustrating a conductive path in a stack type semiconductor device in accordance with example embodiments.  FIGS.  6 A and  6 B  are cross-sectional views taken along a line VI-VI′ in  FIGS.  5 A and  5 B . 
     Referring to  FIGS.  6 A and  6 B , the second wafer W 2  may be positioned over the first wafer W 1 . The upper surface W_F of the first wafer W 1  may face the upper surface W_F of the second wafer W 2 . Thus, the first to fifth right monitoring patterns MPr 1 ˜MPr 5  of the second semiconductor chip  10 - 2  may face the first to fifth left monitoring patterns MPl 1 ˜MPl 5  of the first semiconductor chip  10 - 1 . 
     The connection pattern CP of the first semiconductor chip  10 - 1  may be connected between the second left monitoring pattern MPl 2  and the third left monitoring pattern MPl 3  and between the fourth left monitoring pattern MPl 4  and the fifth left monitoring pattern MPl 5 . The connection pattern CP of the second semiconductor chip  10 - 2  may be connected between the first right monitoring pattern MPr 1  and the second right monitoring pattern MPr 2  and between the third right monitoring pattern MPr 3  and the fourth right monitoring pattern MPr 4 . 
     In example embodiments, the connection pattern CP may include a metal wiring under the monitoring pattern CP. 
     For example, as shown in  FIG.  6 A , the connection pattern CP may be an uppermost metal interconnection layer under the monitoring pattern MP in the first or second wafer W 1  or W 2 . 
     Alternatively, the connection pattern CP may include any one of a plurality of multi-interconnection layers. For example, a wiring structure  180  including at least one contact plug and at least one metal wiring may be interposed between the connection pattern CP and the monitoring pattern MP. The connection pattern CP may have various heights by inserting the wiring structure  180 . As shown in  FIG.  6 B , the connection pattern CP may be exposed through the bottom surface W_B of the wafers W 1 , W 2 , or the semiconductor chips  10 - 1  and  10 - 2  by using the wiring structure  180 . 
     Further, the connection pattern CP of the first wafer W 1  and the connection pattern CP of the second wafer W 2  may be alternately arranged so that the conductive path is not cut off. 
     Referring to  FIG.  7   , when the first wafer W 1  and the second wafer W 2  are bonded to each other, a vertical conductive path VP may be formed based on the vertical connection structure. Further, a horizontal conductive path PP may be formed based on the connection patterns CP that extend from both ends of the vertical conductive path VP in anti-parallel directions. The anti-parallel directions may be parallel directions having a phase difference of 180° or substantially 180°. Thus, an overlap portion might not exist between the connection pattern CP of the first wafer W 1  and the connection pattern CP of the second wafer W 2 . As a result, a conductive path P 1  including the vertical conductive path VP and the horizontal conductive path PP may be formed in the edge regions A 2  of the first and second wafers W 1  and W 2 . 
     In example embodiments, the monitoring pattern MP, corresponding to one end of the conductive path P 1 , may be set as a transmitter Ta. Another monitoring pattern MP that is electrically connected to the transmitter Ta, and may or may not be physically connected to the transmitter Ta, may be set as a receiver Tb. When a test bias (voltage) is applied to the transmitter Ta, a test current may flow through the conductive path P 1  in vertical and horizontal directions of the first and second wafers W 1  and W 2 . The receiver Tb may be electrically connected to a test current measurement member to measure the amount of the test current that is flowing in the conductive path P 1  due to the test bias. A bonding error between the wafers W 1  and W 2  may be detected based on the amount of the test current that is detected by a test current measuring circuit (not shown). 
     For example, when a bonding error occurs between the first and second wafers W 1  and W 2 , which are hybrid-bonded, the resistance of the conductive path P 1  may be greatly increased due to the bonding error. Accordingly, a lower amount of test current may flow through the conductive path P 1  than if there was no bonding error. Therefore, it may be seen that a bonding error between the bonded wafers may be readily detected by measuring the amount of the test current flowing through the conductive path P 1 . It may be noted that when the bonding error results in an open circuit in the conductive path P 1 , there is no current flowing in the conductive path P 1 . 
     In example embodiments, the transmitter Ta may be positioned at the second wafer W 2 , and the receiver Tb may be positioned at the first wafer W 1 . Alternatively, the transmitter Ta may be positioned at the first wafer W 1 , and the receiver Tb may be positioned at the second wafer W 2 . Further, both the transmitter Ta and the receiver Tb may be positioned at the first wafer W 1  or the second wafer W 2 . 
     Further, the transmitter Ta and the receiver Tb may be positioned in the edge region A 2 . Alternatively, the transmitter Ta and the receiver Tb may be positioned in the main region A 1 . Still further, one of the transmitter Ta and the receiver Tb may be in the main region A 1  and the other of the transmitter Ta and the receiver Tb may be in the edge region A 2 . 
       FIGS.  8 A and  8 B  are plan views illustrating a transmitter and a receiver in a stack type semiconductor device in accordance with example embodiments. 
     Referring to  FIG.  8 A , the transmitter Ta may be arranged in the main region A 1 . The transmitter Ta may be electrically connected to a monitoring pattern MPa (hereinafter, transmission monitoring pattern) via a redistribution layer (RDL)  190 . 
     A monitoring pattern MPb (hereinafter, reception monitoring pattern), which may be adjacent to the monitoring pattern MPa and physically spaced apart from the monitoring pattern MPa, may be electrically connected to the receiver Tb in the main region A 1  via the RDL  190 . 
     When the test bias (voltage) is applied to the transmitter Ta in the main region A 1 , the transmission monitoring pattern MPa may also have the test bias (voltage) via the RDL  190 . A test current may result in the conductive path P 1  due to the test bias, and the test current may be received by the receiver Tb, which may be electrically connected to the reception monitoring pattern MPb. The test current may then be measured by the test current measuring circuit (not shown). A bonding error of the wafers W 1  and W 2  may cause the resistance of the conductive path P 1  to change, which may cause the test current to change as the test current is directly related to the resistance in the conductive path P 1 . Thus, the bonding error of the wafers W 1  and W 2 , which are hybrid-bonded, may be detected (or monitored) based on the measured test current. Accordingly, the test bias (voltage) in the transmission monitoring pattern MPa may result in the test current to the reception monitoring pattern MPb through the conductive path P 1  in the edge region A 2 . When the bonding error (or some other error such as a crack in the conductive path P 1 ) results in an open circuit, the test current will be zero amperes. 
     Referring to  FIG.  8 B , a routing pattern  195  may be connected between the transmitter Ta and the transmission monitoring pattern MPa. The routing pattern  195  may be configured to surround the edge of the main region A 1 . The routing pattern  195  may include one end that is connected to the transmitter Ta and the other end that is connected to the transmission monitoring pattern MPa. The conductive path P 1  in the edge region A 2  may be connected between the transmission monitoring pattern MPa and the reception monitoring pattern MPb. The reception monitoring pattern MPb may be connected to the receiver Tb via an RDL  191 . The routing pattern  195  may include a conductive layer on a level that is different from a level of the monitoring pattern MP and the connection pattern CP. A reference numeral CT may indicate a contact or a contact plug that is connected between metal wirings on different levels. 
     Thus, the bonded wafers or the bonded semiconductor chips may further include the routing pattern  195  that is on a different level than the vertical and horizontal conductive paths to monitor the crack and the bonding error at various positions of the bonded wafers. 
       FIG.  9    is an enlarged cross-sectional view illustrating a stack type semiconductor device bonded by a face-to-face bonding process in accordance with example embodiments. 
     Referring to  FIG.  9   , the stack type semiconductor device may include the first and second wafers W 1  and W 2 , which are hybrid-bonded. Each of the first and second wafers W 1  and W 2  may include a semiconductor substrate  110  and a device layer  150  that is integrated on the semiconductor substrate  110 . Further, the first and second wafers W 1  and W 2  may be classified by a plurality of semiconductor chips. For reference,  FIG.  9    shows portions of a semiconductor chip of the first wafer W 1  and a semiconductor chip of the second wafer W 2 . As described above, each of the semiconductor chips may include the edge region A 2  that surrounds the main region A 1 . In addition, the stack type semiconductor device may include the conductive path for detecting the bonding error. The conductive path may include a plurality of vertical connection structures VP and a plurality of horizontal connection structures PP. For example, the plurality of vertical connection structures VP and the plurality of horizontal connection structures PP may be arranged in the edge region A 2  of each of the semiconductor chips of the wafers W 1  and W 2 . 
     Each of the vertical connection structures VP may include a first sub-vertical connection structure SVP 1  and a second sub-vertical connection structure SVP 2 . The first sub-vertical connection structure SVP 1  may be positioned in the first wafer W 1 . The second sub-vertical connection structure SVP 2  may be positioned in the second wafer W 2 . For example, the first and second sub-vertical connection structures SVP 1  and SVP 2  configured to receive a same signal may be bonded to each other to form the vertical connection structure VP. 
     The first sub-vertical connection structure SVP 1  may include a TSV  120 , a conductive pattern  130 , a contact plug  140 , a monitoring pattern MP, and a bonding pattern  160 . The second sub-vertical connection structure SVP 2  may include a bonding pattern  160 , a contact plug  140 , a conductive pattern  130 , and a TSV  120 . The vertical connection structure VP may extend in a first direction D 1 . 
     In example embodiments, the TSV  120  may be formed through the semiconductor substrate  110  of each of the wafers W 1  and W 2 . The conductive pattern  130  and the contact plug  140  may be formed over the TSV  120  to be electrically coupled to the TSV  120 . For example, the conductive pattern  130  may include at least one metal wiring pattern. The contact plug  140  may be formed between the metal wiring patterns. The conductive pattern  130  and the contact plug  140  may be positioned in the device layer  150 . The monitoring pattern MP may be formed on the contact plug  140 . In example embodiments, the contact plug  140  may include one conductive pattern that is formed between the conductive pattern  130  and the monitoring pattern MP. Alternatively, the contact plug  140  may include a multi-layered conductive pattern that is formed between the conductive pattern  130  and the monitoring pattern MP. For example, the monitoring pattern MP may include an uppermost metal layer of the multi-interconnection layers. 
     The bonding pattern  160  may include a copper layer having a high electrical conductivity and good electromigration. 
     The bonding pattern  160  of example embodiments may include a hybrid bonding pattern configured to stably bond the first and second wafers W 1  and W 2  to each other. 
       FIG.  10    is an enlarged cross-sectional view illustrating a hybrid bonding pattern of a stack type semiconductor device in accordance with example embodiments. 
     As shown in  FIG.  10   , a bonding pattern  160   d  of the first wafer W 1  and a bonding pattern  160   u  of the second wafer W 2  may include at least one metal pattern  161  and at least one insulation pattern  163 , respectively. The metal pattern  161  and the insulation pattern  163  may be alternately arranged. For example, the metal pattern  161  may include a copper layer and the insulation pattern  163  may include a silicon oxide layer. 
     The bonding patterns  160   d  and  160   u  may be bonded through the hybrid bonding process with heat. 
     The vertical connection structure VP may provide a vertical conductive path configured to penetrate the stacked semiconductor chips or the stacked wafers. 
     The horizontal connection structure PP may be configured to electrically connect the adjacent vertical connection structures VP with each other. For example, the horizontal connection structure PP may include a connection pattern CP configured to connect conductive patterns or metal wirings in the vertical connection structures VP. As mentioned above, the connection pattern CP may be configured to connect the conductive patterns  130  of the adjacent vertical connection structures VP with each other. Alternatively, the connection pattern CP may be extended from the conductive pattern  130 . 
     The horizontal connection structure PP may be connected to a lower end and an upper end of one vertical connection structure VP that are formed through the first and second semiconductor chips  10 - 1  and  10 - 2 . A lower horizontal connection structure PPd, connected to the lower end of the vertical connection structure VP, may be positioned at the first semiconductor chip  10 - 1 . The lower horizontal connection structure PPd may be extended in a second direction D 2 . The second direction D 2  may be parallel to a surface of the semiconductor substrate  110 . An upper horizontal connection structure PPu, connected to the upper end of the vertical connection structure VP, may be positioned at the second semiconductor chip  10 - 2 . The upper horizontal connection structure PPu may be extended in a third direction D 3 . The third direction D 3  may be slanted compared to the second direction D 2  at an angle of about 180°. Thus, an overlap portion might not exist between the lower horizontal connection structure PPd and the upper horizontal connection structure PPu. 
     By continuously arranging the vertical connection structure VP and the horizontal connection structure PP in the edge region A 2 , the conductive path may be extended in the bonded wafers W 1  and W 2  along the vertical and horizontal directions. 
     A reference numeral  115  may indicate an insulation interlayer between the vertical connection structures VP. Reference numerals  170   a  and  170   b  may indicate test pads that are exposed through the bottom surface of the first wafer W 1 . For example, the test pad  170   a  may correspond to the transmitter Ta in  FIGS.  8 A and  8 B . The test pad  170   b  may correspond to the receiver Tb in  FIGS.  8 A and  8 B . 
       FIG.  11    is an enlarged cross-sectional view illustrating a stack type semiconductor device including stacked four wafers in accordance with example embodiments. 
     Referring to  FIG.  11   , first to fourth wafers W 1 ˜W 4  may be stacked. Each of the first to fourth wafers W 1 ˜W 4  may be divided into a plurality of semiconductor chips. The first to fourth wafers W 1 ˜W 4  may include corresponding pad structures. 
     For example, the first and second wafers W 1  and W 2  may be stacked in the face-to-face bonding process. The third and fourth wafers W 3  and W 4  may also be stacked in the face-to-face bonding process. The second and third wafers W 2  and W 3  may be stacked in the back-to-back bonding process. 
     In the back-to-back bonding process, the bottom surfaces of the wafers may face each other. For example, an external pad  155  may be arranged on the bottom surfaces of the second and third wafers W 2  and W 3 . The external pad  155  may be electrically connected to the TSV  120  in the second and third wafers W 2  and W 3 . The bonding pattern  160  may be formed on the external pad  155 . Thus, the bonding pattern  160  of the second wafer W 2  may face the bonding pattern  160  of the third wafer W 3 . An insulation layer  115  may be formed between stack structures including the external pad  155  and the bonding pattern  160 . The bonding pattern  160  may correspond to the hybrid bonding pad. 
     When the first to fourth wafers W 1 ˜W 4  is bonded to each other, the vertical connection structure VP may be formed through the first to fourth wafers W 1 ˜W 4 . The horizontal connection structure PP may be formed in a lowermost wafer (i.e., the first wafer W 1 ) and an uppermost wafer (i.e., the fourth wafer W 4 ). The lower horizontal connection structure PPd may be extended in the second direction D 2 . The upper horizontal connection structure PPu may be extended in the third direction D 3 . 
     Therefore, the conductive path that extends in the vertical and horizontal directions may be formed in the first to fourth wafers W 1 ˜W 4 . When the test bias is applied to one end of the conductive path, the test current may flow through the conductive path. Thus, whether the bonding of the wafers is normal (acceptable) or not may be determined by measuring the test current. Further, because the conductive path may be formed near the semiconductor chip, the position of the bonding error within the wafer may be accurately recognized. In example embodiments, the horizontal connection structure PPu may be extended from a selected one of the multi-layered conductive wirings (or the multi-interconnection layers:  120 ,  130 ,  140  or MP). 
       FIG.  12    is an enlarged cross-sectional view illustrating a stack type semiconductor device including two wafers bonded by a face-to-face bonding process in accordance with example embodiments, and  FIG.  13    is an enlarged cross-sectional view illustrating a stack type semiconductor device including four wafers bonded by various techniques in accordance with example embodiments. 
     Referring to  FIG.  12   , each of the first and second wafers W 1  and W 2  may include a sub-vertical connection structure SVP and a horizontal connection structure Pd and Pu. The upper surface of the first wafer W 1  may face the bottom surface of the second wafer W 2 . The hybrid bonding pattern  160  may be formed on the upper surface of the first wafer W 1  and the bottom surface of the second wafer W 2 . The first and second wafers W 1  and W 2  may be bonded to each other through the hybrid bonding process. 
     An external pad  155  may be formed on the upper surface of the first wafer W 1 . The external pad  155  may be electrically connected between the bonding pattern  160  and the exposed TSV  120 . An external pad  155  may be formed on the bottom surface of the second wafer W 2 . The external pad  155  may be electrically connected between the monitoring pattern MP and the bonding pattern  160 . In example embodiments, the external pad  155  may include an RDL. 
     Although the first and second wafers W 1  and W 2  may be stacked in the face-to-face bonding process, when the corresponding sub-vertical connection structures SVP are electrically and physically bonded to each other, the vertical connection structure VP may be formed through the stacked wafers W 1  and W 2 . Further, because the horizontal connection structure PP in the first and second wafers W 1  and W 2  may be connected between the vertical connection structures VP, the conductive path may be extended in the bonded first and second wafers W 1  and W 2  along the vertical and horizontal directions. 
       FIG.  12    may show the two wafers stacked in the face-to-face bonding process. Alternatively, at least three wafers may be hybrid-bonded to each other. 
     As shown in  FIG.  13   , each of the first to fourth wafers W 1 ˜W 4  may include a sub-vertical connection structures SVP. The first and fourth wafers W 1  and W 4  may include a horizontal connection structure PPd and PPu respectively configured to connect the adjacent sub-vertical connection structures SVP with each other. As shown in  FIG.  12   , the first and second wafers W 1  and W 2  may be bonded to each other through the face-to-face bonding process. The third and fourth wafers W 3  and W 4  may also be bonded to each other through the face-to-face bonding process. The second and third wafers W 2  and W 3  may be bonded to each other through the back-to-back bonding process, illustrated with reference to  FIG.  9   . Although the wafers may be stacked through various techniques, when the facing sub-vertical connection structures SVP are electrically and physically bonded to each other, the vertical connection structure VP may be formed through the first to fourth wafers W 1 ˜W 4 . Further, because the horizontal connection structure PPd and PPu on the first and fourth wafers W 1  and W 4 , respectively, may be connected between the sub-vertical connection structures SVP, the conductive path may be extended in the bonded first to fourth wafers W 1 ˜W 4  along the vertical and horizontal directions. 
       FIG.  14    is a flow chart illustrating a method of manufacturing a stack type semiconductor device in accordance with example embodiments. 
     Referring to  FIG.  14   , in step S 1 , the wafers may be bonded to each other through the hybrid bonding process. Each of the wafers may be divided into the semiconductor chips. The sub-vertical connection structures and the horizontal connection structures may be arranged in the edge region of the semiconductor chip. The sub-vertical connection structure may be formed through each of the wafers. The uppermost and lowermost wafers, among the wafers, may include the horizontal connection structure configured to connect the adjacent sub-vertical connection structures to each other. The horizontal connection structures in the uppermost wafer and the lowermost wafer may be alternately arranged, without facing each other, to form the horizontal and vertical conductive path having a pulse shape (referring to  FIG.  7   ) in the bonded wafers. 
     After completing the hybrid bonding process, in step S 2 , the bonding failure of the wafers may be detected by utilizing the conductive path. Particularly, the test bias may be applied to one end of the conductive path. The resulting test current may then be measured at the other end of the conductive path. 
     When the measured test current is no less than an allowable range, the bonding process may be determined to be normal. In contrast, when the measured test current is lower than the allowable range, the bonding process may be determined to be abnormal. That is, it can be noted that there may be a misalignment between the upper and lower sub-vertical connection structures, or the connection patterns CP may be disconnected from each other due to a crack formed in the bonding process. In example embodiments, the conductive path, before applying the test bias, may be a conductive wiring structure. The conductive path after applying the test bias may be an actual current flow path. The information of the bonding failure that is obtained in step S 2  may be stored, for example, in a testing apparatus, a packaging apparatus, a controller configured to control the apparatuses, etc. Following bonding processes may be corrected based on the information of any bonding failure(s). 
     In step S 3 , the wafers may then be sawed. However, when bonding failure is determined for all of the bonded wafers, the sawing process might not be performed. If the sawing process is performed, the bonded wafers may be singulated into the stacked chips. In step S 4 , a packaging process may be performed on the stacked chips to form the stack type package. 
     The packaging process may include mounting the semiconductor chips on a package substrate and molding the semiconductor chip and the package substrate with a resin. The packaging process might not be performed on any semiconductor chip deemed to have bonding failure. When the abnormal semiconductor chip is packaged together with the normal semiconductor chip, the abnormal semiconductor chip may have been previously treated to make the abnormal semiconductor chip in the stack type package non-operational. 
     In step S 5 , the stack type package may then be tested. The test process may include generating the conductive path in the semiconductor chips, which may be bonded in the manner substantially the same as that illustrated in step S 2 , to transmit the test current in the vertical and horizontal directions. A test voltage may be applied to the package through an external terminal. When an error is detected in the package test, not the wafer test, it can be noted that the packaging process may be abnormal, and the hybrid bonding process may be normal. Thus, the packaging process may be corrected based on the detected information. 
     The vertical and horizontal current path may flow through the stacked semiconductor chip in the package. A problem, such as a crack of the semiconductor chip, may be tested based on the amount of the test current that is transmitted to the vertical and horizontal current path. 
     Although not depicted in drawings, external terminals, such as solder balls, may then be mounted on the bottom surface of the stack type package. 
     Additionally, while various embodiments in this disclosure described a horizontal connection structure connecting adjacent vertical connection structures for ease of description, an embodiment of the disclosure need not be so limited. That is, an embodiment may have a horizontal connection structure connect non-adjacent vertical connection structures. 
     According to example embodiments, the conductive path including the vertical connection structure and the horizontal connection structure may be formed in each of the regions of the semiconductor chip in which the test pads are arranged. After bonding the wafers to each other, the test bias may be applied to one end of the conductive path to provide the test current through the conductive path. The bonding error of the bonded wafers may be detected by determining the value of the test current. 
     In example embodiments, the semiconductor chips may be hybrid-bonded to each other using the bonding patterns. Alternatively, any semiconductor chips may be stacked during the hybrid bonding process and other semiconductor chips may be stacked in a bump bonding process. Further, the test process of example embodiments may be applied to various memory devices, such as a 3DS memory device and a high bandwidth memory (HBM). 
     The above described embodiments of the present disclosure are intended to illustrate and not to limit any embodiment. Various alternatives and equivalents are possible. The disclosure is not limited by the embodiments described herein. Nor is the disclosure limited to any specific type of semiconductor device. Another additions, subtractions, or modifications are obvious in view of the present disclosure and are intended to fall within the scope of the appended claims.