1. A non-inverting LPF comprising:
a filter input terminal;
a filter output terminal;
a first resistor that is coupled to the filter input terminal and the filter output terminal, wherein the first resistor has a first resistance;
an amplifier having a first input terminal, a second input terminal, and an output terminal;
a first capacitor that is coupled between the filter output terminal and the first input terminal of the amplifier;
a second capacitor that is coupled between the filter output terminal and the output terminal of the amplifier; and
a second resistor that is coupled between the first input terminal of the amplifier and the output terminal of the amplifier, wherein the second resistor has a second resistance, and wherein second resistance is greater than the first resistance.
2. The non-inverting LPF of claim 1, wherein the bandwidth of amplifier is greater than the cutoff frequency of the LPF.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of manufacturing a semiconductor device, comprising the steps of:
(a) forming a pad nitride film on a semiconductor substrate;
(b) etching a portion of the pad nitride film and the semiconductor substrate to form a trench;
(c) depositing a first insulating film on the entire structure so that the trench is buried;
(d) polishing the first insulating film so that the pad nitride film is exposed;
(e) wet etching the first insulating film so that the semiconductor substrate at both sidewalls of the trench is exposed;
(f) performing a SEG process at the condition that the pad nitride film is formed on the semiconductor substrate for only the semiconductor substrate exposed at both sidewalls of the trench to form a silicon growth layer on each sidewall;
(g) forming a second insulating film on the first insulating film so that the trench is buried; and
(h) removing the pad nitride film.
2. The method as claimed in claim 1, wherein the first insulating film or the second insulating film are formed using any one of a SOG oxide film of a family of HSQ, a HDP oxide film, a BPSG oxide film, an USG oxide film, a PSG oxide film and a PETEOS oxide film.
3. The method as claimed in claim 2, wherein the SOG oxide film of a family of HSQ is formed using a fluidity oxide film as a coating source liquid at the rotating force of 1500 through 3000 rpm.
4. The method as claimed in claim 2, wherein the HDP oxide film is formed using SiH4, O2 and Ar gas or SiH4, O2 and He gas as a source gas, by sequentially performing a deposition process at a temperature of 400 through 700\xb0 C. for depositing the HDP oxide film on the entire structure, a CMP process for exposing the semiconductor substrate, and a wet or a dry etch process for exposing a portion of the both inner sidewalls of the trench.
5. The method as claimed in claim 2, wherein the BPSG oxide film is formed using boron and phosphoric having a concentration ratio of 12:4 through 13:6, by sequentially performing a CVD process at a temperature of 400 through 500\xb0 C. for depositing the BPSG oxide film, a CMP process for exposing the semiconductor substrate, and a wet or a dry etch process for exposing a portion of the both inner sidewalls of the trench.
6. The method as claimed in claim 2, wherein the USG oxide film is formed using TEOS and O3 gas, by sequentially performing a deposition process at a temperature of 400 through 600\xb0 C. for depositing the BPSG oxide film, a CMP process for exposing the semiconductor substrate, and a wet or a dry etch process for exposing a portion of the both inner sidewalls of the trench.
7. The method as claimed in claim 1, wherein the SEG process is performed using DCS(SiH2Cl2) gas and HCl gas, wherein the amount of the DCS(SiH2Cl2) gas introduced is 100 through 300 sccm, the amount of the HCl introduced is 20 through 80 sccm, a deposition pressure is 10 through 40 torr and a temperature is 700 through 900\xb0 C.