Switched-capacitor DC-to-DC converters and methods of fabricating the same

#Various embodiments of the present disclosure relate to converters and methods of fabricating the same and, more particularly, to switched-capacitor Direct Current-to-Direct Current (DC-to-DC) converters and methods of fabricating the same.

#Switched power converters used in power supplies may be typically categorized as either switched-inductor converters (SICs) or switched-capacitor converters (SCCs). The SICs may store energy in their inductors while the SICs convert a source of direct current (DC) from one voltage level into another voltage level, and the SCCs may store energy in their capacitors while the SCCs convert a source of direct current (DC) from one voltage level into another voltage level. The SICs may exhibit a wide operating range and a high efficiency. Thus, the SICs have been widely used in application fields of high power. However, there may be some limitations in employing the SICs in compact systems because inductors of the SICs occupy a relatively large area. In contrast, the SCCs may be suitable for low power systems having a compact size because capacitors of the SICs occupy a relatively small area as compared with the inductors of the SICs. Recently, the SCCs have been widely used in mobile systems because of their compact size and low electromagnetic interference.

#In general, in the event that switching elements and capacitors are integrated in a single chip, there may be a limitation in increasing a capacitance value of the capacitors because of a planar area that the capacitors occupy. Moreover, since a high temperature process is used in fabrication of the capacitors, characteristics of transistors constituting the switching elements may be degraded due to the high temperature process. Thus, the capacitors have been separately fabricated from the chip including the switching elements such as the transistors and have been disposed outside the chip.

#Various embodiments of the present disclosure will become more apparent in view of the attached drawings and accompanying detailed description, in which:

#FIG. 1 is a circuit diagram illustrating a switched-capacitor DC-to-DC converter according to an embodiment;

#FIG. 2 is a cross-sectional view illustrating a switched-capacitor DC-to-DC converter according to an embodiment;

#It will be understood that although the terms first, second, third etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element in some embodiments could be termed a second element in other embodiments without departing from the teachings of the present disclosure.

#It will also be understood that when an element is referred to as being located “under,” “beneath,” “below,” “lower,” “on,” “over,” “above,” “upper,” “side” or “aside” another element, it can be directly contact the other element, or at least one intervening element may also be present therebetween. Accordingly, the terms such as “under,” “beneath,” “below,” “lower,” “on,” “over,” “above,” “upper,” “side,” “aside” and the like which are used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the present disclosure.

#It will be further understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.