應用於2.4GHz T/R開關前端電路之靜電放電防護設計

Abstract

隨著CMOS技術的進步與發展，射頻積體電路 (radio-frequency integrated circuits, RF ICs) 也逐漸廣泛實現在CMOS製程中。因此不但可以有效提高晶片的整合度並且降低成本。在CMOS製程中，靜電放電 (electrostatic discharge, ESD) 對於積體電路一直是一項相當重要的可靠度問題，而靜電放電防護設計也非常重要。然而對於射頻積體電路，靜電放電防護設計會帶來不需要的寄生效應，因此能應用在射頻積體電路之靜電放電防護設計除了要有好的靜電放電耐受度之外，還必須要能將其寄生效應的影響降至最低。 本論文提出兩種針對T/R開關前端電路 (T/R switch font-end circuit) 的靜電放電防護設計，第一種靜電放電防護設計可以減少寄生效應的影響，並承受一定的靜電放電轟擊，第二種靜電放電防護設計可以不外加任何靜電放電防護元件，便可以承受一定的靜電放電轟擊。兩者皆可以運用於2.4GHz的T/R開關前端電路。 本論文也提出一種針對傳統T/R開關前端電路的靜電放電防護設計，除了可以減少外加的靜電防護元件，還將矽控整流器 (silicon-controlled rectifier, SCR) 崁入T/R開關中，並由電源端到地端間靜電放電箝制電路 (power-rail ESD clamp circuit) 的偵測電路提供觸發訊號。因此，此架構可以藉由矽控整流器及寄生二極體作為靜電放電路徑，並且運用於2.4GHz傳統T/R開關前端電路。

As the CMOS technology develops so fast, radio-frequency integrated circuits (RF ICs) has been widely implemented in CMOS process. It has the advantage of a high integration and a low cost. Electrostatic discharge (ESD) has been one of the most serious reliability issues of CMOS processes, so ESD protection design is very important. However, undesirable parasitic effect is induced by the ESD protection design in RFICs. Consequently a successful RF ESD protection design needs well ESD protection ability and small parasitic effect. In this thesis, two RF ESD protection designs for T/R switch front-end circuit are proposed. The first one can reduce the parasitic effect and sustain ESD stress. The second one can sustain ESD stress without extra ESD protection device. Both ESD protection designs are applied to 2.4GHz T/R switch front-end circuit. An RF ESD protection design for traditional T/R switch front-end circuit is also proposed in this thesis. The number of the ESD protection devices is reduced in this design. Besides, silicon-controlled rectifier (SCR) is embedded in T/R switch, and the detection circuit, which is used in power-rail ESD clamp circuit, can sent trigger signals to trigger the SCR. The embedded SCR and parasitic diode can provide ESD discharge paths. Moreover, this ESD protection designs are applied to 2.4GHz traditional T/R switch front-end circuit.