Integration of Electrodeposited Ni-Fe in MEMS with Low-Temperature Deposition and Etch Processes

Abstract

This article presents a set of low-temperature deposition and etching processes for the integration of electrochemically deposited Ni-Fe alloys in complex magnetic microelectromechanical systems, as Ni-Fe is known to suffer from detrimental stress development when subjected to excessive thermal loads. A selective etch process is reported which enables the copper seed layer used for electrodeposition to be removed while preserving the integrity of Ni-Fe. In addition, a low temperature deposition and surface micromachining process is presented in which silicon dioxide and silicon nitride are used, respectively, as sacrificial material and structural dielectric. The sacrificial layer can be patterned and removed by wet buffered oxide etch or vapour HF etching. The reported methods limit the thermal budget and minimise the stress development in Ni-Fe. This combination of techniques represents an advance towards the reliable integration of Ni-Fe components in complex surface micromachined magnetic MEMS.

Electroplating of Semiconductor Materials for Applications in Large Area Electronics: A Review

“…Asides semiconductors, other issues such as the influence of different process conditions on mechanical properties of electroplated materials and the control of the integrity of the electroplated layers as it relates to further processing have also been the raised [86,87], but not discussed in this communication.…”

“…techniques such as [77], MOCVD [84], and CSS [85] also require such treatments, as it is evident in the performances of the applications utilised for References [81][82][83]. Asides semiconductors, other issues such as the influence of different process conditions on mechanical properties of electroplated materials and the control of the integrity of the electroplated layers as it relates to further processing have also been the raised [86,87], but not discussed in this communication.…”

Effect of Target Composition and Sputtering Deposition Parameters on the Functional Properties of Nitrogenized Ag-Permalloy Flexible Thin Films Deposited on Polymer Substrates

“…Copper-permalloy films were deposited by co-sputtering, inducing Cu into the permalloy lattice results in very resilient spin scattering and alters their chemical, structural, magnetic, and electrical properties [ 42 ]. Interfacial scattering affects the magnetoresistance of heterogeneous FeCoAg films and the magnetic couplings between the particles are considerably decreased because of the coalescence of the magnetic species [ 43 , 44 ]. Ag concentration in the as-deposited NbCN-Ag thin films were accomplished by adjusting Ag target power to tune the functional properties [ 45 ].…”

Normal Electrochemical Deposition NiFe

“…Summing up the results of the analysis of chemical characteristics of hydrolysis of ferric chloride, it should be noted that researchers in over 65 years [2] conducted NiFe alloy plating and receive preferential deposition of iron in relation to nickel in all formulations electrolyte. Electrolytes used [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] is characterized by a wide range of molar relationship of nickel and iron. The cause of the anomalous codeposition of preferential deposition of iron sources previously not associated with the main feature of iron ionsthe existence of variable Valence iron one and two values in the charge of ions during the hydrolysis of iron salts.…”