1260723 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種半導體基板上的測試鍵，尤指一 種具有鍵狀電路及開爾文結構的測試鍵。 【先前技術】 在半導體製程中’為維持產品品質的穩定’須針對所 生產之半導體元件不斷進行測試。通常在進行各項製程的 同時，亦會採用相同的步驟製作一測試用元件，藉由測量 該測試用元件的各項功能是否正常，以有效控制產品品 質。此外，隨著半導體製程的不斷改進，晶片上所包含的 電晶體數量急速地增加，進而使得用來連接晶片内各層的 介層插塞（via)之數目也急速地增加。為有效地掌控半導 體產品的良率，如何精確地量測介層插塞的電阻值，便成 為一項不可忽視的課題。 請參考第1圖，第1圖為一習知的測試鍵1〇之示意圖。 測試鍵10係採用業界所熟知的開爾文結構（Kelvin structure )，主要是用來量測一介層插塞12之電阻值。測試 鍵10係形成於一半導體基板上，其包含有一第一接觸墊 1260723 第二接觸墊16、-第三接觸墊18 14 9n _ 一第四接觸墊 以及兩料22、24。介層插塞12闕由兩導線22、 :與:個接:墊14、16、18、20連接。當量測介層插塞 之電阻值時’會藉由—探針卡上的探針來接觸四個接觸 Μ、16、18、20。而藉由第一接觸塾14及第二接觸墊 16·’ 一測試電流1會被導人刺試鍵Η)内並流經介層插塞 12，同時，探針卡會藉 二 曰、 ㈢由弟一接觸墊18及第四接觸墊2〇 里測介層插基12兩端的帝网笔,, 、电I至’亚依據所量測得的電壓差 求出介層插塞12的雷阳枯从 J兒阻值。然而，因測試鍵1〇僅包含單 一個介層插塞12，故且 文"各易文到蝕刻負載效應（etching loading effect)的影響。 請參考第2圖及第3 ^ ® 弟2圖為另一習知的測試鍵 之佈線圖’第3圖為第2圖中測試鍵3g之局部剖面圖。 結構’其係形成於—半導體基板 上亚匕㊁有一第一接觸 一— 32、一弟一接觸墊34、複數個電 子組件36、複數個導辦& 、 、 8以及複數個介層插塞40。通常， V體38為金屬導線，而♦ 7 免子組件6是具導電性的擴散區 或疋$體3 8下一金凰風丄 > $中的金屬導線。介層插塞40則用 來將弟一接觸墊32、第〜 〜接觸墊34、電子組件36、導體 38連接在一起。所以， 弟一接觸墊32、電子組件36、導 1260723 體38、介層插塞40以及第二接觸墊34會串聯成一串聯電 路，其中第一接觸墊32與第二接觸墊34分別位於此一串 聯電路的兩端。當測試測試鍵30時，係藉由探針卡上的兩 探針接觸第一接觸墊32、第二接觸墊34，並施加一測試電 壓至第一接觸墊32。正常情形下，會如第3圖所示般，會 有一測試電流I產生，而測試電流I會流經串聯電路中的 電子組件36、介層插塞40、導體38。探針卡會量測所產 生的測試電流I之大小，以計算出第一接觸墊32與第二接 觸墊34之間的等效電阻值，進而估算每一介層插塞40的 電阻值。雖然，測試鍵30的蝕刻負載效應會較小，但因所 求出來的每一介層插塞40的電阻值並非精確’故其應用在 改進及分析半導體製程良率時的功用上有限。 【發明内容】 因此，本發明的目的即在於提供一種新的測試鍵，以 解決上述習知技術的問題。 該測試鍵形成於一半導體基板上，其包含有複數個電 子組件、複數個導體、複數個介層插塞、一第一接觸墊、 一第二接觸墊、一第三接觸墊、一第四接觸墊。該等介層 插塞係用來連接該等電子組件與該等導體。該第一接觸 1260723 墊、該等電子組件、該等導體、料介層插塞以及該第二 接觸墊係串聯成—㈣電路，而該第—接觸塾與該第二接 觸墊分別位於該串聯電路之兩端。該第三接觸塾、該第四 接觸墊、該等導體中之一導體、該等介層插塞中之一介層 插塞以及該等電子組件中之一電子組件構成一開爾文結 構。 藉由。亥開爾文結構可精確地量測單一個介層插塞之電 阻值此外’ m丨試鍵具有多個串聯的介層插塞，故其 姓刻負載效應會較小。 【實施方式】 月^考第4圖及第5圖，第4圖為本發明測試鍵％之 =圖’第5圖為第4圖中測試鍵5()之開_文結構⑹的 =圖1試鍵5G與測試鍵列在結構上非常類似；兩者 取的i別在於測試鍵3〇的串聯電路中的一段被測試鍵 50的—開爾文結構6〇所取代。 _試鍵30相同岐’測試鍵5Q亦形成於 =並包含有-第-接觸㈣、-第二接觸塾34、一 蜀藝56、—第四接觸墊％、複數個電子組件 10 1260723 36〜36’、複數個導體38〜38’，以及複數個介層插塞40。在 本實施例中，導體38、38’為金屬導線，而電子組件36、 36’是導體38、38’下一金屬層中的金屬導線。當然，本發 明並不以此一實施狀況為限，例如：電子組件36、36’亦可 為具導電性的擴散區。介層插塞40則用來將第一接觸墊 32、第二接觸墊34、電子組件36〜36’、導體38〜38’連接在 一起。所以，第一接觸墊32、電子組件36〜36’、導體38〜38’、 介層插塞40，以及第二接觸墊34會串聯成一串聯電路， 其中第一接觸墊32與第二接觸墊34分別位於此一串聯電 路的兩端。 如前所述，測試鍵30的串聯電路中的一段被開爾文結 構60所取代，而構成了測試鍵50。其中，如第5圖所示， 開爾文結構60係由第三接觸墊56、導體38’、電子組件 36’、第四接觸墊構58，以及電子組件36’與導體38’之間 的一介層插塞40所構成。此外，開爾文結構60中的電子 組件36’連接至第三接觸墊56,且其導體38’會連接至第四 接觸墊58，而一特定的介層插塞40則與電子組件36’及導 體38’連接。 當測試測試鍵50時，會藉由一探針卡上的探針來接觸 1260723 四個接觸墊32、34、56、58。此時，探針卡會藉由第一接 觸墊32及第二接觸墊34，輸出一測試電流I至測試鍵50， 以測試測試鍵50各元件間是否正常地連接。若探測卡順利 地將測試電流I輸出至測試鍵50的話，則表示測試鍵50 各元件間正常地連接，而此一測試電流I會由第一接觸墊 ‘ 32，經過各電子組件36〜36’、各導體38〜38’及各介層插塞 40，流至第二接觸墊34 ;然而，若探測卡無法將測試電流 ® I輸出至測試鍵50，則可推斷測試鍵50各元件間有可能連 — 接不正常而造成斷路。除此之外，探針卡會藉由第三接觸 • 墊56及第四接觸墊58來量測電子組件36’及導體38’之間 的介層插塞40兩端之電壓差，並依據所量測得的電壓差求 出此一介層插塞40的電阻值。因此，藉由測試鍵50的結 構設計，不但可以精確地求得單一個介層插塞40的電阻 值，同時又可偵測個元件之間是否正常地連接。 相較於習知技術，本發明之測試鍵因具有一開爾文結 構，故可以精確地求得單一個介層插塞的電阻值，又可避 免受到蝕刻負載效應的影響。此外，因該測試鍵具有多個 串接的介層插塞，故同時又可偵測個元件之間是否正常地 連接。因此在同樣的佈線面積上，本發明之測試鍵可具有 上述多重的功能。 1260723 以上所述僅為本發明之較佳實施例，凡依本發明申請 專利範園所做之均等變化與修飾，皆應屬本發明之涵蓋範 圍。 【圖式簡單說明】 第1圖為一習知的測試鍵之示意圖。 第2圖為另一習知的測試鍵之佈線圖。 第3圖為第2圖中之測試鍵的局部剖面圖。 第4圖為本發明測試鍵之佈線圖。 第5圖為第4圖中測試鍵之_文結構的示意圖。 【主要元件符號說明】 10 、30、 50測試鍵 12， 、40 介層插塞 16、 ‘34 第二接觸墊 20、 58 第四接觸墊 36、 36， 電子組件 60 開爾文結構 14、32 第一接觸墊 18、56 第三接觸墊 22 ' 24 導線 38、38， 導體 131260723 IX. Description of the Invention: [Technical Field] The present invention relates to a test key on a semiconductor substrate, and more particularly to a test key having a key circuit and a Kelvin structure. [Prior Art] In order to maintain the stability of product quality in the semiconductor manufacturing process, it is necessary to continuously test the semiconductor components produced. Usually, while performing various processes, the same steps are used to make a test component, and by measuring whether the functions of the test component are normal, the product quality is effectively controlled. In addition, as semiconductor processes continue to improve, the number of transistors contained on the wafer increases rapidly, and the number of vias used to connect the various layers within the wafer is rapidly increasing. In order to effectively control the yield of the semiconductor product, how to accurately measure the resistance value of the dielectric plug becomes a problem that cannot be ignored. Please refer to FIG. 1 , which is a schematic diagram of a conventional test button 1 。. The test button 10 is based on the well-known Kelvin structure, and is mainly used to measure the resistance value of a via plug 12. The test key 10 is formed on a semiconductor substrate and includes a first contact pad 1260723, a second contact pad 16, a third contact pad 18 14 9n _ a fourth contact pad, and two materials 22, 24. The via plug 12 is connected by two wires 22, :: a pad: pads 14, 16, 18, 20. When the resistance value of the equivalent dielectric plug is used, the four contacts Μ, 16, 18, 20 are contacted by the probe on the probe card. And the first contact 塾 14 and the second contact pad 16 ′′ a test current 1 will be guided by the test button Η ) and flow through the via plug 12 , at the same time, the probe card will borrow two, (3) From the contact pads 18 and the fourth contact pads 2 in the second contact pad 2, the celestial pens at the two ends of the interposer 12 are measured, and the electric I to the sub-measurement voltage difference is used to determine the thunder of the intervening plug 12 The yang is obstructed from J. However, since the test key 1〇 contains only a single via plug 12, it is affected by the etching loading effect. Please refer to Fig. 2 and Fig. 3^2 for another conventional test key wiring diagram. Fig. 3 is a partial cross-sectional view of the test key 3g in Fig. 2. The structure 'is formed on the semiconductor substrate, the first contact 1 - 32, the first contact pad 34, the plurality of electronic components 36, the plurality of guides & , 8 and a plurality of via plugs 40. Typically, the V body 38 is a metal wire, and the ♦ 7 subassembly 6 is a conductive diffusion zone or a metal wire in the body. The via plug 40 is used to connect the contact pads 32, the contact pads 34, the electronic components 36, and the conductors 38 together. Therefore, the first contact pad 32, the electronic component 36, the conductive 1260723 body 38, the via plug 40, and the second contact pad 34 are connected in series to form a series circuit, wherein the first contact pad 32 and the second contact pad 34 are respectively located Both ends of the series circuit. When the test key 30 is tested, the first contact pad 32, the second contact pad 34 are contacted by the two probes on the probe card, and a test voltage is applied to the first contact pad 32. Under normal conditions, as shown in Figure 3, there will be a test current I generated, and the test current I will flow through the electronic component 36, the via plug 40, and the conductor 38 in the series circuit. The probe card measures the magnitude of the test current I generated to calculate the equivalent resistance between the first contact pad 32 and the second contact pad 34, thereby estimating the resistance of each of the via plugs 40. Although the etch load effect of the test key 30 is small, the resistance value of each of the via plugs 40 is not accurate because of its application, so its application is limited in its function of improving and analyzing the semiconductor process yield. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new test key to solve the above problems of the prior art. The test button is formed on a semiconductor substrate, and includes a plurality of electronic components, a plurality of conductors, a plurality of via plugs, a first contact pad, a second contact pad, a third contact pad, and a fourth Contact pad. The via plugs are used to connect the electronic components to the conductors. The first contact 1260723 pad, the electronic components, the conductors, the material interlayer plug and the second contact pad are connected in series to a (four) circuit, and the first contact pad and the second contact pad are respectively located in the series Both ends of the circuit. The third contact pad, the fourth contact pad, one of the conductors, one of the via plugs, and one of the electronic components constitute a Kelvin structure. By. The Heikal structure can accurately measure the resistance value of a single plug. In addition, the 'm丨 test button has a plurality of series plugs in series, so the load effect of the surname is small. [Embodiment] FIG. 4 and FIG. 5 of the monthly test, FIG. 4 is a test key %=Fig. 5 of the present invention, and FIG. 5 is a diagram of the test key 5 () in the fourth figure. The test button 5G is very similar in structure to the test key column; the difference between the two is that the segment of the test circuit 3〇 is replaced by the Kelvin structure 6〇 of the test key 50. _ test button 30 is the same 岐 'test button 5Q is also formed in = and contains - first contact (four), - second contact 塾 34, a 蜀 56 56, - fourth contact pad%, a plurality of electronic components 10 1260723 36~ 36', a plurality of conductors 38~38', and a plurality of via plugs 40. In this embodiment, the conductors 38, 38' are metal wires and the electronic components 36, 36' are metal wires in the next metal layer of the conductors 38, 38'. Of course, the present invention is not limited to this implementation. For example, the electronic components 36, 36' may also be conductive diffusion regions. The via plug 40 is used to connect the first contact pad 32, the second contact pad 34, the electronic components 36-36', and the conductors 38-38'. Therefore, the first contact pad 32, the electronic components 36-36', the conductors 38-38', the via plug 40, and the second contact pad 34 are connected in series to form a series circuit, wherein the first contact pad 32 and the second contact pad 34 are respectively located at both ends of the series circuit. As previously mentioned, one of the series circuits of the test key 30 is replaced by the Kelvin structure 60 to form the test key 50. Wherein, as shown in FIG. 5, the Kelvin structure 60 is composed of a third contact pad 56, a conductor 38', an electronic component 36', a fourth contact pad structure 58, and a via between the electronic component 36' and the conductor 38'. The plug 40 is constructed. In addition, the electronic component 36' in the Kelvin structure 60 is coupled to the third contact pad 56, and its conductor 38' is coupled to the fourth contact pad 58 while a particular via plug 40 is associated with the electronic component 36' and the conductor. 38' connection. When the test key 50 is tested, the 1260723 four contact pads 32, 34, 56, 58 are contacted by the probes on a probe card. At this time, the probe card outputs a test current I to the test key 50 through the first contact pad 32 and the second contact pad 34 to test whether the components of the test key 50 are normally connected. If the probe card smoothly outputs the test current I to the test button 50, it means that the components of the test button 50 are normally connected, and the test current I will pass through the first contact pad '32, through the electronic components 36 to 36. ', each of the conductors 38 to 38' and each of the via plugs 40 flow to the second contact pad 34; however, if the probe card cannot output the test current ® I to the test key 50, it can be inferred that the test key 50 is between the components It is possible to connect - it is not normal and cause an open circuit. In addition, the probe card measures the voltage difference across the via plug 40 between the electronic component 36' and the conductor 38' by the third contact pad 56 and the fourth contact pad 58 and is based on The measured voltage difference is used to determine the resistance value of the via plug 40. Therefore, by designing the structure of the test key 50, not only the resistance value of the single dielectric plug 40 but also the normal connection between the components can be accurately determined. Compared with the prior art, the test key of the present invention has a Kelvin structure, so that the resistance value of a single dielectric plug can be accurately obtained, and the influence of the etching load effect can be avoided. In addition, since the test button has a plurality of serially connected plugs, it is possible to detect whether or not the components are normally connected. Therefore, the test key of the present invention can have the above multiple functions in the same wiring area. The above description is only the preferred embodiment of the present invention, and all the equivalent changes and modifications made by the patent application scope of the present invention should be covered by the present invention. [Simple Description of the Drawing] Fig. 1 is a schematic diagram of a conventional test button. Figure 2 is a wiring diagram of another conventional test key. Figure 3 is a partial cross-sectional view of the test key in Figure 2. Figure 4 is a wiring diagram of the test key of the present invention. Figure 5 is a schematic diagram of the structure of the test key in Figure 4. [Main component symbol description] 10, 30, 50 test key 12, 40 interlayer plug 16, '34 second contact pad 20, 58 fourth contact pad 36, 36, electronic component 60 Kelvin structure 14, 32 first Contact pads 18, 56 third contact pads 22' 24 wires 38, 38, conductor 13