Clean and Conductive Wafer Bonding for MEMS

Yun, Chang-Han; Martin, Jack; Chen, L; Frey, Tim

doi:10.1149/1.2982860

Cited by 22 publications

(16 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Au can not be processed in CMOS lines due to the high diffusivity of Au). Interconnects to form 3D structures by wafer bonding are almost exclusively realized with Cu [4 -6], while sealing frames in hermetically sealed devices may be formed by Au [7] or Al [3]. Metal bonding is suitable for high vacuum applications mainly due to its total lack of outgasing during bonding process (e.g.…”

Section: Introductionmentioning

confidence: 99%

Metal Thermocompression Wafer Bonding for 3D Integration and MEMS Applications

et al. 2010

View full text Add to dashboard Cite

Metal bonding layers are used in various wafer bonding applications in MEMS and more recent in wafer-level 3D integration and optoelectronics. The bond process investigated in this paper is thermocompression. The most used metals for such applications are Cu, Au and Al, each of them with specific requirements for the wafer bonding process. While Au use doesn't face the problem of surface oxidation, both Cu and Al surfaces are covered by native oxides when exposed to ambient atmosphere: the oxidized surfaces impact on bonding process results, so their condition is crucial for successful process. The main process conditions for Cu-Cu and Al-Al bonding are reviewed and examples are presented.

show abstract

Section: Introductionmentioning

confidence: 99%

Metal Thermocompression Wafer Bonding for 3D Integration and MEMS Applications

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Table 1 lists experimental parameters extracted from a number of reports on Al-Al wafer bonding. In established processes, a high pressure-usually several tens of MPa (Yun et al 2008a;Malik et al 2014Malik et al , 2015-is used to break the oxide in order to establish diffusion channels for Al atoms. As a calculation shows (Rebhan and Hingerl 2015), the elastic energy is much too low to influence the bonding between atoms directly but the applied stress and the resulting strain breaks up the surface layer.…”

Section: Introductionmentioning

confidence: 99%

“…As a calculation shows (Rebhan and Hingerl 2015), the elastic energy is much too low to influence the bonding between atoms directly but the applied stress and the resulting strain breaks up the surface layer. The wafers are bonded at high temperatures, usually in the range of 400-550°C (Yun et al 2008a;Cakmak et al 2009;Froemel et al 2011;Malik et al 2014Malik et al , 2015. In recent experiments, Malik et al were able to reduce the required bonding temperature to about 350°C by depositing the Al metallization layer onto an intermediate SiO 2 layer (Malik et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Surface pretreated low-temperature aluminum–aluminum wafer bonding

et al. 2017

View full text Add to dashboard Cite

Aluminum-aluminum wafer bonding is becoming increasingly important in the production of CMOS microelectromechanical systems. So far, successful bonding has required extreme processing temperatures of 450°C or more, because the chemically highly stable oxide layer acts as a diffusion barrier between the two aluminum metallization layers. By using the ComBond Ò system, in which a surface treatment and subsequent wafer bonding are both performed in a high vacuum cluster, for the first time successful Al-Al wafer bonding was possible at a temperature of 150°C. The bonded interfaces were characterized using C-mode scanning acoustic microscopy and transmission electron microscopy, and featured areas of oxide-free, atomic contact.

show abstract

“…2 Al is an attractive choice of metal due to its CMOS compatibility. Successful Al thermocompression bonding has been reported, [3][4][5][6][7] but reports about a combination of hermetic and reliability properties are missing.…”

mentioning

confidence: 99%

“…Due to shrinkage of the device packaging size below 0.05 cm 3 , rejection leak rates mentioned in MIL-STD-883 are no longer valid. 8 More stringent rejection rates for volumes below 0.01 cm 3 are given in MIL-STD-750E. Traditionally, hermeticity was determined by a gross bubble test along with a He fine leak test.…”

mentioning

confidence: 99%